3D Printing- Medical Applications

Aidan KellyCalifornia Polytechnic State University, San Luis Obispo1 Grand AvenueSan Luis Obispo, CA 93410

BioMed CentralFloor 6, 236 Gray's Inn RoadLondon, United Kingdom

May 29, 2015

Dear BioMed Central,

Enclosed is a technical report titled “3D Printing: The Future of the Medical Field.” This report is intended to teach individuals about the current use of 3D printers in the medical field, as well as to persuade others that this technology will soon revolutionize the medical industry. I am writing this letter in hopes of being published in BioMed Central’s vast database of technically focused journals.

The information in this document was composed from secondary articles taken from reputable databases. Several references are taken from BioMedCentral.com. The articles used refer to current methods of production regarding to different aspects of the medical field as well as new methods involving rapid prototyping.

I would like to thank my partners and colleagues Will McInnis, Nico Rush, and Austin Mattmiller for their tremendous contribution to this document.

I highly appreciate your review of the document to follow. Feel free to contact me by email with any questions or comments regarding the report or publication.

Respectfully,

Aidan Kelly

Aidan KellyBiomedical Engineering StudentCalifornia Polytechnic State University, San Luis [email protected]

3D Printing:The Future of the Medical Field

Aidan KellyAustin Mattmiller

Will McInnisNico Rush

Undergraduate Engineering StudentsCalifornia Polytechnic State University

Last Updated: June 2015

Abstract

The landscape of technology is one that is constantly evolving and morphing as not only new inventions are created but also as previously existing ones are reincarnated to perform entirely new tasks. 3D printing technology has been around since 1984, but its potential is still in its infancy stage of development. The new developments being created and discovered have been monumental in the advancement of the medical field. This paper discusses the applications 3D printing has towards the medical field specifically geared towards the formation of prosthetics, organs, external devices, and food. More specifically, the material will encompass the claims of how 3D printing will produce more customized prosthetics which improve the quality of life for amputees and those suffering from Amelia, save lives and increase efficiency of organ donations through ulterior measures, provide affordability through cheaper means of production of external medical devices, and possibly provide an avenue to feed an exponentially growing global population with proper nutrition. Secondary research has been conducted by means of technical databases found primarily using Academic Search Premier in addition to peer-reviewed articles.

Key Terms: 3D printing, prosthetics, organs, external devices, amelia, organ donations

3D Printing: The Future of the Medical Field

ii

Table of Contents

List of Figures...........................................................................................................................iv1.0 Introduction..........................................................................................................................12.0 Rapid Prototyping Prosthetics..............................................................................................2

2.1 Transradial...............................................................................................................22.2 Socket Fitting...........................................................................................................4

3.0 3D Printing Organs..............................................................................................................63.1 Organ Repair............................................................................................................63.2 3D Modeling for Operations....................................................................................73.3 3D Printing Full Implantable Organs.......................................................................83.4 Tissue Forms............................................................................................................9

4.0 Printing External Applications for Human Body...............................................................104.1 3D Printed Medical Accessories............................................................................104.2 Bioprinting Skin Tissue.........................................................................................11

4.2.1 Technology Used to Bioprint Skin Tissue...........................................124.2.2 Applications of Bioprinted Artificial Skin...........................................12

4.3 Bioprinting Cartilage.............................................................................................144.4 Printing of Surgical Models...................................................................................16

5.0 3D Printing Food................................................................................................................185.1 Types of Applications............................................................................................195.2 Food Customization...............................................................................................20

5.2.1 Nutricition Manipulation.....................................................................215.2.2 Consistency and Hardness...................................................................22

5.3 Applications to Space Exploration.........................................................................225.3.1 Search for a Solution............................................................................235.3.2 Directly Printing for Astronauts...........................................................245.3.3 AstroGro..............................................................................................25

5.4 Possible Need in the Future...................................................................................266.0 Conclusion.........................................................................................................................27References................................................................................................................................28


iii

LIST OF FIGURESFigure A. ...................................................................................................................................2Figure B.....................................................................................................................................3Figure C.....................................................................................................................................4Figure D.....................................................................................................................................4Figure E......................................................................................................................................5Figure F......................................................................................................................................6Figure G.....................................................................................................................................7Figure H.....................................................................................................................................8Figure I.......................................................................................................................................8Figure J.......................................................................................................................................9Figure K...................................................................................................................................11Figure L....................................................................................................................................13Figure M...................................................................................................................................14Figure N...................................................................................................................................15Figure O...................................................................................................................................16Figure P....................................................................................................................................17Figure Q...................................................................................................................................18Figure R...................................................................................................................................20Figure S....................................................................................................................................21Figure T....................................................................................................................................23Figure U...................................................................................................................................24Figure V. .................................................................................................................................25


iv

1.0 Introduction

1.0 INTRODUCTIONAccording to the American Transplant Foundation, “more than 123,000 people in the United States are currently on the waiting list for a lifesaving organ transplant. On average, 21 people die every day from the lack of available organs for transplant in the United States alone.” In conjunction, according to the American Burn Association, “there are around 1 million burn victims in need of medical attention every year in the United States alone.” In addition, according to a new report by the U.S. Department of Agriculture, “17.4 million American families, almost 15 percent of U.S. households, are now "food insecure," an almost 30 percent increase since 2006. This means that, during any given month, they will be out of money, out of food, and forced to miss meals or seek assistance to feed themselves.” Many of these families are also in danger of severe malnourishment. Finally, as population increases, more individuals than ever are in need of prosthetic limbs to aid them in living a normal life.

While these problems are quite diverse in nature and seemingly unrelated, they are all issues that could be solved with the increased application of 3D printers to the medical field. 3D printing, or rapid prototyping, is a currently underutilized practice that, among other fields, has taken huge strides in improving quality of life by making medical practices more efficient and safer.

Advancements in technology have increased precision of customization in prosthetics to formerly inconceivable levels. 3D printed prosthetics have proven to be more affordable and better suited for the wearer leading to a higher demand than ever before.

Organ printing is gaining viability and is taking small steps to completely displace the current method of collecting organs for those in need. Similarly, printers currently have the capabilities to print skin directly onto living beings, a capability that could completely replace current invasive, more expensive skin grafting.

Finally, with the population growing at such a rapid rate, 3D printing food could be the answer to providing the necessary quantity while also allowing customization that could aid malnourished or overweight individuals. This food could also prove to be the answer for providing sustenance for astronauts.


1

2.0 Rapid Prototyping Prosthetics 2

2.0 RAPID PROTOTYPING PROSTHETICS

3D printing in the medical field has been seen to carry many advantages to several different aspects of the field. Regarding prosthetics, 3D printing or rapid prototyping, allows engineers and doctors to work together to develop advanced prosthesis while simultaneously reducing cost and time of production. Rapid prototyping is not limited to specific forms of prosthesis, yet it has been shown to be advantageous for many different applications, some of which include: maxillofacial, transradial, and orthopedic.

2.1 Transradial

A transradial amputee is an individual that suffers from an amputation below the elbow and above the hand. Current methods for fabricating prosthesis for transradial amputees begin with a specialist prosthetist creating mold casts of the individual’s amputated area. The prosthetist then uses this cast along with a combination of pre-designed casts to layer material on to form the prosthetic. This process is very labor intensive, taking months to create a prosthetic that may not fit ideally. Current methods are being tested that involve multi-dimensional scanners and rapid prototyping to create prosthetics.

Multi-dimensional scanning devices are able to capture intricate shapes quicker and easier than the traditional molding methods. These 3D pictures can then be uploaded to computer modeling programs to be examined. Once examined and analyzed, prosthetist are then able to design a prosthetic limb around the critical junction between flesh and machine. Furthermore, computer aided modeling is used to design the entirety of the prosthesis. Having the ability to print the prosthetic attachment allows prosthetist to design around few spatial and manufacturing parameters. Upon completion of the computer-aided design, the file can be transferred to a 3D printer to begin forming. Depending on several variables, some of which include size, intricacy and materials, the 3D printer can print a prosthetic anywhere from several hours to a few days.

Figure A: Rapid Prototyped Prosthetic HandSource: Biomed Central



With advances in rapid prototyping being used across the medical field, advantages to this new form of production are becoming unmistakable. In the development of transradial prosthesis, the use of rapid prototyping allows doctors to create a perfect fit for the patient. Previous methods of production were so labor intensive that if the first prosthesis did not fit correctly time and cost would be considered to decide whether a new prosthesis should be created or if the former should be modified. Now that the prosthesis can be imaged and printed using multi-dimensional modeling, the initial discrepancies in fit are both easier to avoid while being far easier to correct and reproduce. Coinciding with ease of production comes a decrease in cost of production. Transradial prosthesis are seen as out of reach to many amputees today due to the price associated with them. Transradial prosthesis can easily exceed $25,000 due to its heavy dependence on a multitude of factors. (Gretsch, Lather, Paddada, Deeken, Wall, and Goldfarb, 2015).

Figure B: Rapid Prototyped Prosthetic Hands Source: Gibbard, J. 3D printed robotic prosthetic hand makes Intel finals. Retrieved June 2, 2015.

Pulled from a credible article, a team has devised a way of producing transradial prosthesis for close to $300 using rapid prototyping (Gretsch et al.,2015). This dramatic difference in price can open doors to thousands of individuals who otherwise may believe prosthesis are not an option. The team produced a prototype that was used by a young female who provided positive feedback on the operation. The prototyped arm featured a hand that had independent thumb movement as well as finger movement. Independent thumb movement is characteristic of high-end prosthetics, ones that would not be found for less than $1000. The young female’s family said the affordability can open doors for young individuals due to the previous dilemma regarding growing out of the prosthetics (Gretsch et al, 2015). Furthermore, a significant reduction in cost can mean life-changing prosthetics can be reachable for those in developing countries, where this technology is virtually unknown.



Figure C: Design for Transradial Prosthesis

Source: Prosthetics and OrthoticsInternational

2.2 Socket Fitting

Fabricating prosthetic sockets has posed many challenges to prosthetists since they began production. The proximity between a prosthetic and the body is a critical junction that can determine whether prosthesis is a solution or not. Due to the irregularities between almost every prosthetic-body interaction, extreme attention to detail must be used during fabrication. Multi-dimensional scanning allows prosthetists to obtain data regarding minute changes in surface structure. Once a geographic model is obtained and analyzed, rapid prototyping can produce prosthetics in shapes that would otherwise be difficult to produce due to dimensional parameters as well as time constraints.

Figure D: 3D Model of Knee Source: Prosthetics and Orthotics International



The team of Hsu, Huang, Lu, Hong, and Liu (2010) were able to conduct an in vitro test using a rapid prototyped socket versus a mold fitted socket. The test used a cadaver to simulate pressures and motion almost identical to what a human would experience. The goal for this study was to determine if a rapid prototyped socket would provide a feasible alternative to the traditional methods for fabrication while also seeking to improve on the discomfort normally felt by the end user. The test revealed that the results were similar between both prosthetic sockets. The team concluded that rapid prototyping provides a more time and cost efficient method to socket production while still maintaining the fit necessary for a socket prosthetic.

Figure E: 3D Printed Socket TestingSource: Prosthetics and Orthotics International


3.0 3D Printing Organs 6

3.0 3D PRINTING ORGANS

Organ production and repair is another emerging application in the field of 3D printing. Rapid prototyping organs and tissues that can be surgically put into the human body provides many benefits to the future. The 3D printer can use just about any material to produce an object. Gels, groups of cells, and material for scaffolding can pass through a 3D printer head and be layered on top of each other to create an organ. Research is being done with this use of 3D printers to potentially save many lives through the repair of damaged organs or replacement of old ones without a donor.

3.1 Organ Repair

One area where research is being done is on the use of 3D printers to physically lay cells on the damaged organ to regrow damaged tissue. This process requires open surgery with the 3D printer head going in and layering the damaged area of for example a heart of a patient with new heart cells that will replace the damaged cells. Figure F shows an example of a damaged heart. The 3D printer is manned by a surgeon, who can strategically place new, healthy cells in the damaged area that connects to the surrounding heart tissue.

Figure F: Directly Bioprinting Heart Cells Adapted from Kusaka, M. (2015)

The heart can then be repaired and function as if it had not been damaged at all. This method was made possible through research that has proven we can produce tissues that mimic tissues and current cells in our body. Without this ability, one would be unable to produce replacement organisms. This method is still in the developmental stage. It is currently being tested to verify its usefulness and eliminate any possible errors.



3.2 3D Modeling for Operations

It is currently possible to 3D print a full organ model. This model can be used to teach and help plan surgeries. The kidney model was helpful to show the blood vessels and features of the kidney to help surgeons and nurses recognize the anatomical features during the operation. Figure G shows the 3D printed model of a kidney surgeons used to plan an operation. The 3D model weighs 178g and the actual kidney weighs 183g. This makes the 3D model a very accurate representative of the actual kidney (Kusaka, 2015).

Figure G: 3D Printed Kidney ModelAdapted from Kusaka, M. (2015)

Surgeons preformed the kidney transplant using the 3D printed model of a kidney to help guide the operation. After the operation was complete, the surgeons recorded the operation to have been advantageous because they were able to make the operation safer and reduce the risk of donor death during surgery (Kusaka, 2015). The use of 3D modeling in the future to assist surgeons in planning and preforming operations is going to make many operations easier and safer. Surgeons can use 3D printing and modeling technology, for example, is to create a replica of a patient’s pelvic cavity to plan and even practice the operation. Figure H shows a surgeon planning and practicing kidney removal and placement. This hands on practice combined with an accurate life size 3D printed model will help surgeons make operations like a transplant safer. In the future we can expect this kind of 3D modeling to be used everywhere.



Figure H: 3D Printed Model of Pelvic CavitySource: Adapted from Kusaka, M. (2015)

3.3 3D Printing Full Implantable Organs

The printing of full organs is an emerging solution to an increasing problem faced around the world. The organ is made out of living cells that are identical to ones that make up the organs in our body. For example, we can use kidney cells to 3D print a kidney or liver cells to print a liver. However, there are still a few complications in this early phase of trying to produce a functioning organ. An organ needs blood vessels to keep stay alive and get nutrients to the inner cells. Jordan Miller, doctor and researcher at the University of Pennsylvania, came up with the idea of 3D printing a mold out of sugar to serve as blood vessel holes, and then build the organ around the sugar mold. After the organ is complete they wash away the sugar with water leaving blood vessels that are strong enough to withstand the blood pressure of the body (Harmon, 2013)

This technique is still being tested, but so far it has been proven to work. Figure I shows a computer-generated design of an organ on the left and the organs vascular network on the right. The sugar mold is then placed where the 3D printed organ will be produced. The 3D printer layers the organ cells around the sugar mold. The orange and purple parts of the image are the blood vessel tubules that have been left behind from the sugar rinse to allow blood to get into and out of the organ.

Figure I: 3D Model of Blood Vessel NetworkSource: Adapted from (Schely, 2015)



The process of using sugar to make a blood vessel network has only just been created. We are still at the beginning stages of 3D printing capabilities in the medical field and in the near future we will be seeing this technology take over the medical industry. When we are finally able to produce a functioning and long lasting organ with 3D printers we will help save about 100,000 lives a year that are on the waitlist for an organ transplant (Harmon, 2013)

3.4 Tissue Forms

There are still many applications for 3D printing that are in development. Figure J shows a timetable for when we can expect certain uses to be available.

Figure J: Timeframe for Development of 3D printed biotissuesAdapted from Murphy (2014)

The two dimensional portion of printing was developed focusing on applications such as skin. Hollow tubes such as blood vessels are in line to be developed next. Hollow organs such as the bladder will hopefully come after. The ultimate long-term goal, however, is the creation of functioning solid organs. The two dimensional organs have already been fabricated and are likely to be the first type of bio-printed tissue to be transplanted in patients. Hollow tubes like blood vessels, tracheas, and urethras are currently being developed and will likely be the next type of bio-printed tissue ready for transplant. Hollow organs are more complex and will take longer to develop. Solid organs are the most complex, but even though there are challenges to overcome we are making gains in research with vascularization and innervation (Murphy, 2015).


4.0 External Applications to The Human Body 10

4.0 PRINTING EXTERNAL APPLICATIONS TO THE HUMAN BODY

3D printing has been utilized in the medical field for many years in ways that most people are unaware of. The technology for 3D printing items made of plastic has been around for a long time compared to the technology needed for bioprinting. Industries making medical products made from plastics were able to take advantage of this technology ever since its creation. A great example of this is the making of hearing aids. Everyone’s ear is built differently, which means that every hearing aid has to be made separately. Companies were not able to start manufacturing their own hearing aids on a large scale; instead, each hearing aid had to be made by hand. With present 3D printing technology, companies are able to take a scan of the patient’s ear, design, and print a hearing aid fairly quickly. This provides a quicker and cheaper process, delivering the hearing aid to the patient in a matter of hours rather than weeks. This process became extremely popular and was quickly adopted as the easiest and best way to create hearing aids. Around 10,000,000 of the hearing aids in circulation today throughout world were created using a 3D printer (Scharma, 2013).

4.1 3D Printed Medical Accessories

3D printing has been utilized in the medical field for many years in ways that most people are unaware of. The technology for 3D printing items made of plastic has been around for a long time compared to the technology needed for bioprinting. Industries making medical products made from plastics were able to take advantage of this technology ever since its creation. A great example of this is the making of hearing aids. Everybody’s ear is built extremely differently, which means that every hearing aid has to be made separately. Companies were not able to start manufacturing their own hearing aids on a large scale; instead, each hearing aid had to be made by hand. With present 3D printing technology, companies are able to take a scan of the patient’s ear and design and print a hearing aid fairly quickly. This provides a quicker and cheaper process, delivering the hearing aid to the patient in a matter of hours rather than weeks. This process became extremely popular and was quickly adopted as the easiest and best way to create hearing aids. Around 10,000,000 of the hearing aids in circulation today around the world was created using a 3D printer (Scharma, 2013)



Figure K: 3D Printed Hearing AidSource: Adopted from Scharma (2013)

You may know Align Technology as the ones behind Invisalign braces, the invisible alternative to traditional metal braces that have become increasingly more popular over the past few years. Invisalign braces are made of a strong plastic material that gradually shifts teeth in place. In order to do this, dentists take a scan of the patient’s teeth and send it in to Align Technology. They are then able to print each patient’s Invisalign braces individually and send it back to the dentist. This allows customization for each patient. Align Technology had to create a material that wasn’t already being used in 3D printers when they started. This plastic used in their products is strong enough to shift teeth in place while also being resistant to change from constant wear and tear from the user.

4.2 Bioprinting Skin Tissue

Skin tissue is one of the most essential types of tissue in terms of replacement in the human body. According to the American Burn Association, there are around 1 million burn victims in need of medical attention every year in the United States alone. In the past, the best way to treat burn wounds would be to cover the wounded area with an autograft. An autograft is a section of skin from an undamaged part of the patient’s body that is placed on the wounded area in order to promote growth in the surrounding cells. Although surgeons usually take the autograft from a place on the body usually unseen by others such as the upper thigh, the surgery can still be extremely invasive depending on the severity of the burn being treated.



4.2.1 Technology Used to Bioprint Skin Tissue

Recently, scientists have been looking for an easier way for burn victims to be treated. Artificial skin tissues have been generated as a replacement for skin grafts. Three-dimensional bioprinting of skin works in the same way as three-dimensional printing of any other object. A consumer can place a mixture of human cells (in this case skin cells) and other support materials that allow the cells to grow inside of an inkjet printer. The inkjet printer can then print layers of these cells in such a way that these layers interact to form one cohesive tissue. Printing skin tissue provides a huge advantage over skin grafts. Rather than having to conduct an invasive surgery in order to produce a skin graft for their patient, doctors would be able to print a graft that would be suitable for surgery directly in the operating room.

4.2.2 Applications of Bioprinted Artificial Skin

Many companies have put their own touch on this concept of bioprinting skin tissue. Since 2007, the company Organovo has been developing and improving their technology to 3D print viable, living, skin tissue. In fact, Organovo has produced skin tissue so close to the real thing that the cosmetic company L’Oreal has partnered with Organovo to use their 3D printed skin tissue to test L’Oreal’s cosmetics. L’Oreal has grown their own skin tissue from skin cells donated by patients, but has determined that the process of 3D printing the skin to be a much faster process that produces the same results as growing skin tissue (Plaugic, 2015). A professor at Wake Forest University also developed his own way of bioprinting skin. Professor James Yoo developed a three-dimensional bioprinter that is able to print the skin cells directly onto a wound of a patient. This bioprinter is equipped with a scanner that can take a digital scan of the wound being treated and upload it to software that analyzes the wound to see how many layers of skin tissue need to be printed. The bioprinter then is able to print the tissue directly onto the wound. This specialized bioprinter still has some work to be done before it is available to medical professionals, but so far the printer has been proven successful at treating a wound on the knee of a pig and they have began testing the machine on humans (Yoo, 2013).

Researchers working in the regenerative medicine department at the Hannover Medical School in Germany have been testing the viability of this artificial skin tissue in mice. They found mice with injuries to their outer skin tissue and placed a portion of the 3D printed artificial skin tissue on the wounded area. This proved to be extremely effective at replicating actual skin tissue in mice, provoking growth of the blood vessels in surrounding tissues to grow through the artificial skin tissue, providing the tissue with the nutrients it needs to continue growing and become a part of the mice’s body. With this technology proving to be effective at replicating actual skin tissue, the applications in humans should start to become more and more prevalent as the technology improves. The technology should be available to work on humans within the near future. (Michael et al., 2013).



Figure L: Mouse wound before and after bioprinted skin has been grafted. Notice the presence of blood vessels in the after picture only 11 days after the skin has been grafted onto the wound.Source: Adapted from Michael et al. (2013)



4.3 Bioprinting Cartilage

Another area of three-dimensional printing that has been explored is the process of 3D printing cartilage. Cartilage is most common in body parts such as: the ear, nose, and joints. Injuries to the cartilage in the knee, commonly known as the meniscus, have become increasingly more common in high-level sports. In order to combat this, different biomaterials such as nanofibrillated cellulose and alginate are being combined with cartilage cells to act like human cartilage tissue. This mixture was then fed through a bioprinter to acquire the right shape and texture to properly mimic cartilage tissue. This particular mixture was proven to be extremely effective at promoting cell growth in cartilage tissue, showing 86% cell viability after seven days. (Markstedt et al., 2015) Professor Hod Lipson at Cornell University is also developing a way to 3D bioprint cartilage tissue in patients. He used a three-dimensional bioprinter to take cells from a sheep’s torn meniscus and print a completely new, identical meniscus. Currently, Lipson is working on a way to 3D print the missing part of the torn meniscus directly onto the sheep meniscus. This could potentially revolutionize the way we perform surgeries in the future. (Khalid, 2014).

Figure M (A) 3D printed grid using cross linking method (B) Shape deforms while being squeezed (C) Shape reforms immediately after relieved from pressure (D) 3D printed human ear (E and F) 3D printed sheep meniscusSource: Adopted from Markstedt (2015)



Figure N: 3D Printed Skin OrganSource: Adapted from (Murphy, 2014)

Figure N is a 3D printed ear and nose. It is currently possible to print the skin organ. Surgeons are able to transplant the skin tissue onto a patients face if they have been in an accident where they lost part of their face. The skin is the first part of the human body that we can print and transplant.



4.4 Printing of Surgical Models

3D printing has proven to be an asset to the surgical field in more ways than one. When fitting a titanium bone plate to a patient receiving reconstructive jaw or hip surgery, surgeons must put their patient under anesthesia during the fitting and surgery. Recently, hospitals have been using 3D printers to print a model of the patient’s injury instead. A machine is able to take a scan of the patient’s bone and reproduce this scan as a 3D model in CAD software, which can then be sent to a 3D printer and printed as a physical model. Doctors can then use this model to fit the titanium plates without putting the patient under anesthesia or interfering with the wound in any way. This method is much more cost efficient and also provides for a much safer procedure as the patient is under anesthesia for a shorter period of time (Cohen, Laviv, Berman, Nashef, & Abu-Tair, 2009).

Figure O: Fitting a hip implant into a model of a patient’s injured hipSource: Adapted from Replica3dm.com



Rapid prototyping also allows surgeons and doctors to examine parts of the body that would otherwise be impossible to do in vitro. The reproduction of joints with deformities or abnormalities through 3D printing allows doctors to physically examine a portion of the body prior to operation, leading them to a better solution and knowledge base. This can be extremely useful when working with musculoskeletal disorders, where a unique solution is required for most cases. The use of rapid prototyping combined with 3D scanning means these replica body parts can be produced quickly and with little cost. A few of the drawbacks to multi-dimensional replication are the inability to view internal structure as well as resolution limitations due to the quality of printer being used. (Starosolski, Kan, Rosenfeld, Krishnamurthy, and Annapragada, 2013)

Figure P: Scanning and Modeling of Knee Joint Source: Pediatr Radiol Pediatric Radiology


5.0 3D Printing Food 18

5.0 3D PRINTING FOOD

As 3D printing research continues and the practice evolves to further encompass more of the manufacturing industry, it seems to be growingly apparent that the technology will move to incorporate the creation of food. According to field expert Mims (2013), “Additive manufacturing’s two key strengths, geometric complexity and economic viability at low volume of production, naturally translates into food applications.” 3D food printing closely replicates the process in non-food based rapid prototyping. This new method of production could even evolve to run at a more optimal level with lower cost due to the ease of shifting shapes and low cost of the materials involved.

Figure Q Diagram of 3D Printer Set up to Print Food Source: Adopted From Mims, C (2013, May) The audacious plan to end hunger with 3-D printed food



5.1 Types of Applications

According to Southerland (2011), “there are three main types of 3D printing applications related to the manufacturing of food and other food related items: rapid tooling, powder binding, and extrusion based rapid manufacturing.” This assertion made in 2011 holds true to 3D printing today. Southerland goes on to elaborate on the functions of these applications. Rapid tooling involves using conventional powder binding 3D printing to fabricate master models from which silicon molds are made and food materials cast. Powder binder 3D printing uses a combination of different sugars to produce edible forms directly rather than create the molds themselves. Extrusion based rapid manufacturing is commonly used and utilizes materials that include potato, chocolate and cream cheese. (p. 819-822)

The investigation of food as a material used in conjunction with these technologies is a growing area of interest. These systems can be used independently for a simplified process or in conjunction with one another for more complex manufacturing process that in turn could be more rewarding.



The dispenser used creates a model of three-dimensional objects by layering the food from the cartridges held in the nutrient storage cylinders. According to Serizawa (2014), “The same way ink is used to carry out printing in a desktop printer, agar solution, a jelly-like substance obtained from algae, is used to propel the manufacturing of food.” Agar’s gelation deeply depends on temperature. Therefore, temperature control of the solution is important to mold optimal shapes because the physical crosslinking network of agar’s solution is instable. In modern 3D edible gel printers, four kinds of soft food prepared from agar and gelatin can be printed. The compression tests of the printed soft food samples are done on these various types of gel; the results of these tests show a variance of both hardness and consistency. Because of this variation between the gels, it is possible for the user to choose the hardness and consistency using this technology and the proper materials. (p. 2-4)

Figure R: Food Being Dispensed from Nutrient StorageSource: Adopted From Matus, M (2013, February) 3D Printers Could Some Day Feed Astronauts in Space

5.2 Food Customization

Personalization of food is nothing new. Varying recipes to create larger portions, different tastes, and adding ingredients to change textures is not a new trend but rather one that has always been present. However, often times this customization comes at a high price of fine dining, hiring a personal chef, or living in a home with experienced cooks to get the customization that is preferable and sometimes required.



5.2.1 Nutritional Manipulation

One of the major advantages of a 3D printer is that it provides personalized nutrition. It does so by customizing how much of what ingredient in the recipe is needed whether it be decreased trans-unsaturated fats, increased protein density, or larger portioning, all by programing the system with an easer friendly interface. If an individual is male, female, or a person with a temporary or permanent illness they will have personal, unique dietary needs. A 3D printer will be able to take these needs and preferences into account and produce a product that will satisfy these specifications every time food is produced. This level of customization can have substantial benefits aside from making the food look more festive and colorful. Creating food catered specifically to a person’s taste buds could aid picky eaters who refuse to eat food they are not comfortable with. It could also help overweight or obese individuals who would be able to receive all the necessary daily nutrients while reducing the calorie count and negating the fat content. Alternatively, those suffering from anorexia or charitable organizations interested in donating food to nations where hunger is a daily concern could print food with high caloric values and nutritious fats that could prove to be essential for those individuals.

Figure S: Meal Containing 3D Printed Food ItemsSource: Adopted From Mosendz, P (2014, May) 3D-Printed Food Actually Looks (and Tastes) Pretty Delicious



5.2.2 Consistency and Hardness

By using 3D printing to manufacture food an individual can manipulate the texture of food and choose whether to make it harder or softer at the touch of a button. Biggs J (2014) interviewed printing outlet Biozoon who commented, “This application could prove to be integral in assisting those with dysphagia, a condition that makes swallowing food extremely difficult. This is extremely common in the elderly community, where over 60% of senior citizens have trouble swallowing food.” (p. 1-2) To look beyond just the elderly, this condition is also present in the general populous and is a common symptom for those recovering some certain surgical procedures such as a tonsillectomy. Those with this condition are often in pain when swallowing normal food and placed at a higher rate of choking. Companies such as Biozoon use “molecular gastronomy to create food that can be printed using a standard extruder-based printer.” (p. 1-2) The food solidifies and is completely edible but when it’s eaten it quickly dissolves in the mouth. This could save lives by ensuring they don’t aspirate food crumbs into their lungs. The powder mixtures currently available enable universal implementation so that family caregivers, professional cooks, and nurses can easily make the new diets.

5.3 Applications to Space Exploration

While the primary focus of this document is to entail the applications to medicine and nutrition, it is important to note the tangents that this goal of increased nutrition and efficiency could provide. The application of 3D printing food has caught the eye of the global space exploration community. NASA specifically feels that the many uses 3D printing provides could be the long sought after conclusion to their concerns of food consumption and storage on prolonged missions into space.



5.3.1 The Search for a Solution

The various space exploration programs of the world’s nations are becoming more motivated through ambition to find the best possible way to provide food to their astronauts on prolonged missions. Focusing specifically on the United States efforts according to Dunbar B (2013), “as NASA ventures farther into space, whether redirecting an asteroid or sending astronauts to Mars, the agency will need to make improvements in life support systems, including how to feed the crew during those long deep space missions.” (p. 2-3) Dunbar goes on to elaborate on his research conducted with the agency’s officials stating, “NASA's Advanced Food Technology program is interested in developing methods that will provide food to meet safety, acceptability, variety, and nutritional stability requirements for long exploration missions, while using the least amount of spacecraft resources and crew time.” Currently, they are hosting competitions for independent companies and individuals to come up with the best solutions possible. These companies are being provided with grants from NASA that have been increasing as the problems appears to be more urgent with advancements in other aspects of long-term space exploration.

Figure T: Pizza In the Process of PrintingSource: Adopted From 3ders.org (2013, October) NASA-funded 3D food printer prints pizza



5.3.2 Directly Printing Food for Astronauts

From the same report conducted by Dunbar, “The current food system being utilized by NASA wouldn't meet the nutritional needs and five-year shelf life required for a mission to Mars or other long duration missions.” Because refrigeration and freezing require significant spacecraft resources, current NASA provisions consist solely of individually prepackaged shelf stable foods, processed with technologies that degrade the micronutrients in the foods. The issue lies in the balance between creating food that is nutritionally viable while keeping a shelf life that will not expire for the duration of the mission. 3D printing is just one of the many technologies that NASA is investing in to create the new knowledge and capabilities needed to enable future space missions while benefiting life here on Earth. The technology currently available with 3D printing allows a shelf life of up to 30 years, more than enough time for any current and future missions planned for NASA, and allows nutritional customization that will exceed the current standards set for astronauts.

Figure U: AstroGro Pod Sustainable Cycle Source: Adopted From Tampi, T (2015, April) Space Farming with AstroGro’s 3D Printed Smart Pod



5.3.3 AstroGro

The winner of a recent competition in 2015 to find a solution was AstroGro, a team of California Institute of Technology students whose idea was to discover a way to print chambers that can foster food growth rather than print the food itself. The AstroGro pod is an efficient automated and sustainable micro-farm that makes the maximum use of limited resources to grow food. The idea is that, via the printed pods, food can be grown in an artificial environment, eliminating the need to transport food to space stations or planets. This reduces precious weight in a space flight and also enables astronauts to decide what they want to grow since the environment can be controlled for a variety of plants. With a renewable source, living in space can be sustained for longer. The filaments that the pods are made of can also be recycled, saving on additional build material.

Figure V: AstroGro Pod Prototype Source: Adopted From Tampi, T (2015, April) Space Farming with AstroGro’s 3D Printed Smart Pod



5.4 Possible Need in the Future

Anjan Contractor, a mechanical engineer with a background in 3D printing that recently won a $125,000 grant from NASA to explore the nutritional possibilities of printing, envisions a future where 3D printing plays a significant role in daily life. According to his interview conducted by Mims (2013), “He sees a day when every kitchen has a 3D printer, and the earth’s 12 billion people feed themselves customized, nutritionally-appropriate meals synthesized one layer at a time, from cartridges of powder and oils they buy at the corner grocery store. Contractor’s vision would mean the end of food waste, because the powder his system will use is shelf-stable for up to 30 years, so that each cartridge, whether it contains sugars, complex carbohydrates, protein or some other basic building block, would be fully exhausted before being returned to the store.” (p. 1-3) This would revolutionize the way that individuals purchase food by requiring fewer trips to the store and creating jobs manufacturing and distributing the cartridges that fuel the printers. In addition, with the global population expanding at an exponential rate, consciousness for the environment will become increasingly important with each year. Limiting humanity’s carbon footprint is a stated goal of nearly every nation so placing further research and resources into 3D printing applications is a priority.


6.0 Conclusion 27

6.0 CONCLUSION

3D printing has emerged as a revolutionary technology over the past few decades. The benefits rapid prototyping bring to the medical field are only recently being realized. Like many other technologies, 3D printing is growing at a rapid pace, leaving a boundless field to be improved on. The use of rapid prototyping is already being seen as advantageous in the fields of prosthetics, organ research, and external body applications. With more research placed into the industry, 3D printing has the capabilities to replace many processes used in these fields entirely. In addition the benefits are beginning to be recognized in the nutritional industry due to rapid advancements and interest through organizations like NASA. It will not be long before this advanced technology will play a prominent role in our everyday lives


References 28

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