Skype-Interview

‘My Academic History and µPAD-Solution’

Arne Lüker, 30th of Jan. 2013, IIT Genua/Italy

arnelueker@aim.com

www.arne-lueker.de

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GIVEN TOPICExtract:

‘µPAD-

Solution’

µPad and Electroactive Polymers (EAP)

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• Minimal actuator displacement: ≥ 5 μm• A minimal force of ≥ 5 - 10 mN• A practical upper limit on the diameter of the actuator is ≤ 3 mm • The device should be light in weight so it doesn’t cause extra fatigue to

the user.• The actuator including the connecting cables should not limit the

natural motion of the human being.• The operating frequency should be around 250 Hz, since this is more

perceivable at low amplitudes of fingertip penetration.• Ability to create a moving stimulus (not stationary, so operating at a

vibrating mode)• Ability to generate fluctuating stimulus (variable magnitude and

frequency of the force produced by the actuator on the fingertip)

Requirements for an Actuator

Design requirements derived from physiological studies of human tactile perception:

Micro Electroactive Elastomer Pin (MEEP)

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• Pin diameter: 1 mm• Force: ~ 50 mN• Field: ~ 100 kV/mm• Displacement: ~ 1 mm

Phenomenological ModelPhysical Model

equivalent electromechanical pressurevacuum permittivitydielectric constant of the polymerthickness of the elastomer film

Simple Model

http://en.wikipedia.org/wiki/Dielectric_elastomers

case t « r

t

rp

t

rpz 2

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z

cross-sectional area

p: inflation pressuresɵ, sz: circumferential, axial stress

Challenges and Motivations

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http://www.emk.tu-darmstadt.de/mems/forschung/eap/taktile-displays/

DE materials: e.g. acrylic adhesives, polyurethane, silicone elastomers and selectively solvatedtriblock copolymers derived from poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) (*

*) actuations ≤ 245%, coupling efficiencies 92% at electric fields of 22 V/m

Challenge 1: MEMS-process of MEEP

Challenge 2: Synthesis of DE-materials

Challenge 3: Modification of DE-material

Interesting Challenge and Motivation for the next two years with a Great Impact

on different areas of applied sciences!

Thanks!

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More information on www.arne-lueker.de