Mechanical Hand Lesson Plan - Rochester Institute of ... Biomechanical Hand Lesson Plan Page 2 The TEAK Project Rochester Institute of Technology ! ACTIVITY OVERVIEW Mechanical Hand

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Rochester Institute of Technology

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THE$TEAK$PROJECT:$$ $ $ $TRAVELING$ENGINEERING$ACTIVITY$KITS$

Biomechanical Hand

Partial support for this project was provided by the National Science Foundation's Course, Curriculum, and Laboratory Improvement (CCLI) program under Award No. 0737462. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

TEAK Biomechanical Hand Lesson Plan Page 2

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ACTIVITY OVERVIEW

Mechanical Hand Kit Overview Students completing this kit will create a working mechanical finger that they can take home after the activity. The kit is designed to show students an example of an engineering design that duplicates human motion, which could be used to improve the quality of life for someone with disabilities. This kit focuses primarily on the design and fabrication of the mechanical hand and fingers, engineering problem solving, engineering teamwork, and practical applications.

Activity Time Description

Introduction Discussion 10-15 min Introduce bioengineering terms and applications

Mechanical Hand Fabrication

30-35 min Students construct a working mechanical finger out of LEGOs, tape, straws and string.

Final Group Discussion 10-15 min Recap activity and discuss potential design improvements

Learning Objectives By the end of this lesson, students should be able to…

• Explain what bioengineering is • Solve an engineering problem • Follow a procedure to build a prototype • Comprehend similarities/differences between a biomechanical finger and a human finger

NYS Learning Standards Standard 1: Engineering Design

• Design a structure or environment (e.g., a neighborhood) using modeling materials such as LEGO Duplo blocks, model vehicles, model structures, etc.)

Standard 5: Technological Systems

• Will apply technological knowledge and skills to design, construct, use, and evaluate products and systems to satisfy human and environmental needs.

• Assemble simple systems Intermediate Standard 1: Analysis, Inquiry and Design

• Describe the differences and similarities among engineering systems, natural systems, and social systems.


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TABLE OF CONTENTS$

Instructor Preparation Guide…………… .. ………………………………………………………………………5!Bioengineering Overview ....................................................................................................................................... 4!Biomechanics Overview ......................................................................................................................................... 4!Material Preparation ............................................................................................................................................... 5!

Bioengineering Discussion ....................................................................................................................................... 7!Background Information ......................................................................................................................................... 7!Bioengineering Group Discussion: 5 Minutes ........................................................................................................ 7!

Mechanical Hand Activity Introduction ................................................................................................................. 8!Background Information ......................................................................................................................................... 8!Simplified Definition: 5 Minutes ............................................................................................................................ 8!Biomechanics Group Discussion: 5 Minutes .......................................................................................................... 9!Learning Objectives .............................................................................................................................................. 10!Materials ............................................................................................................................................................... 10!Procedure .............................................................................................................................................................. 10!

Concluding Discussion ........................................................................................................................................... 11!Biomechanical Hand Activity Handout ........................................................................................................... 12-14!Image Sources ......................................................................................................................................................... 14!Revisions .................................................................................................................................................................. 14!

Signifies Group Discussion Signifies Activity


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INSTRUCTOR PREPARATION GUIDE

Bioengineering Overview Bioengineering is the use of engineering principles to facilitate challenges in the fields of biology and medicine. Bioengineering applies engineering design principles to model any living systems. Biomechanics Overview Biomechanics is the application of mechanical principles to living organisms. Mechanical engineers apply their engineering principles and knowledge of physics and mechanics to simulate living objects. Areas of biomechanics that will be covered in this lesson include prosthesis, robotics, and materials. Prosthesis helps disabled humans perform tasks that they otherwise could not perform. Robotics is helping doctors perform surgeries that take a great deal of precision and control. The materials needed for these applications of biomechanics must be selected based on the many different functions and environments a system will be used in.

Figure 1 – Robotic Hand with Air Muscles

Robotic hands, such as the one in Figure 1 can achieve the same range of motion as a human hand can. Doctors can use this technology to perform procedures without being in the same room as the patient being operated on. Air muscles attached to wires simulate the effect of a real human muscle. The concept for this robotic hand stems from simple mechanical models, like the one in Figure 2, which the students will construct.

Figure 2 – Mechanical Hand Activity


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Material Preparation Material must be prepared prior to teaching. Materials are based on a class size of 25 students.

1. LEGOs – 75 Pieces 2. Rubber Bands – 25 Pieces cut once 3. Masking Tape – 25 Pieces at 4’ lengths 4. String – 25 Pieces at 12” lengths 5. Foam Board – 25 Pieces sized 3”x2” 6. Straw – 100 Pieces at 3/4” Lengths 7. Dixie Cups – 25 Pieces

Put 3 LEGOs, a rubber band, a piece of string, and 4 pieces of straw into a Dixie cup. Place a piece of the foam board over the top of the cup, like it’s a lid. Wrap the length of tape around the cup/foam board to hold everything together.


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Biomechanical Hand

DURATION 45-50 Minutes

CONCEPTS Bioengineering Biomechanics

Prosthetics Medical Applications


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BIOENGINEERING DISCUSSION

Background Information Bioengineering is the application of engineering principles to address challenges in the fields of biology and medicine. Bioengineers are motivated to make breakthroughs on human health while promoting environmental sustainability.

Bioengineering Group Discussion: 5 Minutes (Pose the following questions to the group and let the discussion flow naturally…try to give positive feedback to each child that contributes to the conversation.)

Q: What do you think bio (biology) means?

• The study of life and a branch of the natural sciences that studies living organisms and how they interact with each other and their environment.

• The study of the environment. • The study of living organisms and living systems.

Q: What do you think engineering is? What do you think it means to be an engineer?

• A technical profession that applies skills in: o Math o Science o Technology o Materials o Anatomy o Environmental Studies

Discuss with the students what bioengineering is and the broad scope of areas that bioengineering includes. For this discussion, provide students with examples of bioengineered products and applications.

• Bioengineering applies engineering principles in the fields of medicine, biology, robotics, and any other living system.

• Examples of products that have been bioengineered are: o Prosthetic Joints o Artificial Limbs o Hearing Aids o Artificial Organs – Heart, Lungs, etc. o Dialysis Machines o Contact Lenses


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MECHANICAL HAND ACTIVITY INTRODUCTION

Background Information This kit is designed to give students a better understanding of how engineers solve engineering problems and design systems to improve the quality of life for those with disabilities. It further explains how engineers must analyze and acquire data from a biological system in order to design and fabricate a biomechanical product. The main focus of this kit is the design and fabrication of the hand and fingers, engineering problem solving, engineering teamwork, and practical applications. Mechanical or robotic limbs can serve an array of purposes. First, they can help people with disabilities live a more normal life by serving as an artificial limb. Secondly, they can help doctors perform complex medical procedures with fine precision and accuracy. Finally, as a new technology develops, these devices continue to improve the life of those with disabilities.

Simplified Definition: 5 Minutes Biomechanics

• Taking knowledge of mechanical systems and applying them to living organisms. EX: Prosthetic joints and robotics

Prosthesis (Prosthetics): • An artificial extension that replaces a missing body part. Used to replace body parts lost by injury,

missing from birth, or to supplement a defective body part. Air Muscle

• A man-made “muscle” that uses air pumped into tubing to mimic the actions of human muscles. As the tubing expands, it causes the plastic mesh to get shorter. This causes a “contraction” of the muscle. The mesh works like a Chinese finger trap.

Robotic Hand

• A mechanical hand that is stationary and is typically used to perform medical procedures. Telesurgery

• New technology using a robotic hand that allows a doctor in one location to perform surgery at another location. The doctor wears a glove that transmits his movements to the robotic hand controlled by air muscles.


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Biomechanics Group Discussion: 5 Minutes (Pose the following questions to the group and let the discussion flow naturally…try to give positive feedback to each child that contributes to the conversation.)

Q: Have you ever seen someone wearing a prosthetic (mechanical) limb?

• (There will be various answers.) Q: Why would someone need a prosthetic limb?

• To replace a lost or missing limb. • To perform a task they cannot do. • Increase strength or motion of human limb.

Q: What do engineers need to know to create a prosthetic limb?

• Range of motion • Strength • Size • Location • Purpose

Q: Do you think there is a difference in the design of a prosthetic hand compared to a robotic hand?

• YES! o Prosthetic hands are designed to look like a human hand where robotic hands are designed for

functionality. o Prosthetic hands utilize a person’s remaining muscle, while a robotic hand needs air muscles o Prosthetic hands are streamlined, while robotic hands may be bulky and take up lots of room

Biomechanical+Hand+Activity+–+30+Minutes+


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Learning Objectives By the end of this exercise, students should be able to…

• Follow a procedure to build an apparatus • Determine similarities/differences between a biomechanical finger and a human finger

Materials Each finger construction kit contains:

• LEGOs – (3) Pieces • Rubber Bands – (1) Piece cut once • Masking Tape – (1) Piece cut to a 4’ length • String – (1) Piece cut to a 12” length • Foam Board – (1) Piece sized 3”x2” • Straw – (4) Pieces cut to 3/4” lengths • Dixie Cups – (1) Piece

Procedure 1. Pass out a biomechanical finger construction kit to each student. Instruct the students to carefully unwrap

the tape that is around the kit and hang it off their desk. (They will be using this tape to build their hand, so make sure that they understand they need to try not to tangle it.) The students should then lay all of the pieces on their desk.

2. Pass out an activity handout to each student/group.

*** Assembly instructions are on the activity handout. ***

3. Once everyone is ready to begin, the instructor will start going through the assembly instructions step by step. In between each step, the instructor should walk amongst the students and check that they are building their finger correctly.

4. Once all the students have correctly assembled their fingers, have them try to pick up various objects around the classroom. While this is happening, walk around to each group and let the students measure their grip strength with the hand dynamometer.

End+Biomechanical+Hand+Activity+


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CONCLUDING DISCUSSION

Q: What were you able/unable to pick up with your hand/fingers? • (There will be various answers.)

Q: What were some of your limitations?

• Strength of material • Size of fingers • Spacing of fingers • Shape of hand/fingers

Q: Think about how hard you squeezed on the hand dynamometer. What do you think would happen if you tried to squeeze that hard with your mechanical hand?

• The wood would break • The string would break • The tape would rip

Q: What are some improvements you would make to have your mechanical hand work like a human hand?

• Use a stronger material (metal or plastic) • Use a material with more friction • Make a thumb

TEAK Biomechanical Hand Lesson Plan Page 12 !

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BIOMECHANICAL HAND ACTIVITY HANDOUT

1. Lay the three LEGOs next to each other the long way (like a finger). Make sure that the bumps are facing upwards.

2. Tape across the two seams in the middle of the finger.

3. Turn the finger over (so the bumps are face down) and place the rubber band down the middle of the finger sections, as shown.

4. Tape around the middle of each LEGO, making sure to leave the ends of the elastic un-taped, as shown. Make sure you tape the rubber band tightly.

5. Bend the short end of elastic over itself and tape around the finger once more to prevent the rubber from slipping.

6. Tape the inside of the finger (the bumpy side of the LEGO) to the piece of foam board.


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7. Turn the hand over and tape the rubber band to the hand.

8. Tape the piece of string over the end of the finger.

9. Flip the hand over so that the bumps are facing up. Thread the pieces of straw onto the string.

10. Tape one straw to the middle of each finger section and one to the hand, as shown below.

11. You have finished building your biomechanical finger!! You can operate the finger by pulling the string. Try using your finger to pick up the Dixie cup, or other small objects.


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IMAGE SOURCES

[1] Parekh, Alan. Tactile Robotic Hand with Air Muscles. 2007. Hacked Gadgets Forum. JPEG file. http://hackedgadgets.com/2007/07/25/tactile-robotic-hand-with-air-muscles/

REVISIONS

Date Changes Made Changes Made By

10/13/2009 Updated the assembly procedure to account for the change from wood to LEGO finger pieces. Added more detail to the procedure and discussion sections. Also, updated pictures.

Heather Godlewski

3/19/2013 Edited for grammar and syntax issues. Reorganized the format.

Todd Jackson

Documents

Mechanical Hand Lesson Plan - Rochester Institute of ... Biomechanical Hand Lesson Plan Page 2 The TEAK Project Rochester Institute of Technology ! ACTIVITY OVERVIEW Mechanical Hand