Printing Functional Systems

Hod LipsonMechanical & Aerospace Engineering

Computing & Information ScienceCornell University

Computational Synthesis Labhttp://ccsl.mae.cornell.edu

Cornell UniversityCollege of Engineering

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Adaptation

• Changing environments, tasks, internal structures – Behavioral adaptation– Morphological adaptation

Breeding machines in simulation

Lipson & Pollack, Nature 406, 2000

Emergent Self-Model

Bongrad, Zykov, Lipson (2006) Science, in press

Damage Recovery

With Josh Bongard and Victor Zykov

Making Morphological Changes in Reality

Printable Machines

Multi-material processes

LinearMotor

ThreadedRod

SyringeBarrel Plunger

Deposition via Syringe Extruder Tool

>250um

MaterialFluid

Reservoir

PIEZO-ACTUATOR

Material FluidReservoir

~30V,DC-10kHz

Deposition via Ink-Jet

~100um

Continuous pathsVolume Fill

High-resolution patterning, mixingThin films (60nm)

Multi-material RP

Illustration: Bryan Christie

Our RP Platform

Fabrication platform: (a) Gantry robot for deposition, and articulated robot for tool changing, (b) continues wire-feed tool (ABS, alloys), (c) Cartridge/syringe tool

Some of our printed electromechanical / biological components: (a) elastic joint (b) zinc-air battery (c) metal-alloy wires, (d) IPMC actuator, (e) polymer field-effect transistor, (f) thermoplastic and elastomer parts, (g) cartilage cell-seeded implant in shape of sheep meniscus from CT scan.

Printed Active Materials

With Evan Malone

Zinc-Air Batteries

With Megan Berry

Zinc-Air Batteries

IPMC Actuators

IPMC: Ionomer

Ionomeric Polymer-Metal Composite

• “Ionic polymer”• Branched PTFE

polymer• Anion-terminated

branches.• Small cation

First printed dry actuator

• Quantitative characterization

• Improve service life– Reduce solvent

loss– Reduce internal

shorting

• Improve force output, actuation speed

Embedded Strain Gages

Silver-doped silicon

Robot finger sensor

IPMC: Ionomer

Ionomeric Polymer-Metal Composite

• “Ionic polymer”• Branched PTFE

polymer• Anion-terminated

branches.• Small cation

First printed dry actuator

• Quantitative characterization

• Improve service life– Reduce solvent

loss– Reduce internal

shorting

• Improve force output, actuation speed

IPMC Actuators

ResultsPower [W]

Force [mN]

100% Printable Robot

Printed Agarose MeniscusCell Impregnated Alginate Hydrogel

CAT Scan

Direct 3D Print after 20 min.Sterile Cartridge

Multi-material 3D Printer

Multicell print

With Daniel Cohen, Larry Bonassar

The potential of RP

• Physical model in hours

• Small batch manufacturing

• New design space

• Design, make, deliver and consume products

• Freedom to create

Learning from the history

• Similarity with the computer industry– In the ’50s-’60s computers…

• Cost hundreds of thousands of $• Had the size of a refrigerator• Took hours to complete a single job• Required trained personal to operate• Were fragile and difficult to maintain

• Vicious circle– Niche applications Small demand– Small demand High cost

Niche applications

Digital PDP-11, 1969

Stratasys Vantage, 2005

Exponential Growth

Source: Wohlers Associates, 2004 report

RP Machine Sales

The Killer App?

Honeywell’s “kitchen Computer”

• Robust

• Low cost

• Hackable

Precision: 25µmPayload: 2KgAcceleration: 2gVolume: 12”x12”x10”

Fab@Home

Fab@Home

Fab@Home: “Fablab in a box”

www.FabAtHome.com

Digital Structures

Reconfigurable systems

Zykov, Mytilianos, Adams, Lipson Nature (2005)

• Fukuda et al: CEBOT, 1988

• Yim et al: PolyBot, 2000

• Chiang and Chirikjian, 1993

• Rus et al, 1998, 2001

Murata et al: Fracta, 1994

Murata et al, 2000

Jørgensen et al: ATRON, 2004

Støy et al: CONRO, 1999

Programmable Self AssemblyStochastic Systems:

scale in size, limited complexity

Whitesides et al, 1998

Winfree et al, 1998

Saul Griffith, Nature 2005

Hardware implementation: 2D

White, Kopanski & Lipson, ICRA 2004

Implementation 1: Magnetic Bonding

With Paul White, Victor Zykov

Construction Sequence

High Pressure

Low Pressure

Construction Sequence

Construction Sequence

Construction Sequence

Construction Sequence

Construction Sequence

Reconfiguration Sequence

Reconfiguration Sequence

Implementation 2: Fluidic Bonding

Accelerated x16

With Paul White, Victor Zykov

Real Time

With David Erickson, Mike Tolley

a) t = 18.8 s b) t = 19.3 s c) t = 19.5 s d) t = 19.7 s

e) t = 4.9 s f) t = 8.6 s g) t = 14.3s h) t = 15.6s Figure 5. Assembly and Disassembly of 500 μm Silicon Tiles on PDMS Substrate

500 µm

With Mike Tolley, Davis Erickson

Tile dimension: 500μm

Randomized Machines

Dictyostelium Cytoskeleton of a mammalian cellDon Ingber, Scientific American 1998 With Chandana Paul

Particle RoboticsTensegrity Robotics

Grand Challenges

• Can we design machines that can design other machines?

• Can we make machines that can make other machines?

• Can we make machines that can explain other machines?