Smart Polymer Material as Artificial Muscle Actuator

Transcription

1 Smart Polymer Material as Artificial Muscle Actuator Yusuf Wibisono Advanced Materials Science and Engineering

2 Actuator Motion-generating device A mechanical device for moving or controlling a mechanism or a system. Applications: Robotic & prosthetic mechanisms Pumps Valves

3 Problems Actuator Small-scale system Conventional Pneumatic Actuator Electromagnetic Actuator Hydraulic Actuator Problems: Poor Efficiency Heavyweight Difficulty fabricated High Cost Novel motion-producing device Importance Performance Parameters Specific energy density Strain Actuation pressure Response time Environmental tolerance Reliability Fabrication complexity Solve Problems: High degree of mobility Lightweight Various shapes produced easily Low Cost Core Question: What is the novel material which have good performance indicators to use as actuator in small-scale system? Electroactive Polymers?

4 Electroactive Polymers (EAPs) Polymers whose shape is modified when a voltage is applied to them. As actuators, they are characterized by the fact that they can undergo a large amount of deformation while sustaining large forces. Often called artificial muscles. Two principal classes: Dielectric EAPs Actuation is caused by electrostatic forces between two electrodes which squeeze the polymer. Ionic EAPs Actuation is caused by displacement of ions inside the polymer.

5 Papers selection Keywords: 1 st : actuator* (11510 papers) 2 nd : artificial muscle (159 papers) 3 rd : polymer dielectric (12 papers) 3 papers (compare the materials) Papers selected 1. Ron Pelrine, Roy Kornbluh, Jose Joseph, Richard Heydt, Qibing Pei, Seiki Chiba High-field deformation of elastomeric dielectrics for actuators MATERIALS SCIENCE & ENGINEERING C 11 (2000) R. Palakodeti, M.R. Kessler Influence of frequency and prestrain on the mechanical efficiency of dielectric electroactive polymer actuators MATERIALS LETTERS 60 (2006) Kwangmok Jung, Joonho Lee, Misuk Cho, Ja Choon Koo, Jae-do Nam, Youngkwan Lee and Hyouk Ryeol Choi Development of enhanced synthetic elastomer for energyefficient polymer actuators SMART MATERIALS AND STRUCTURES 16 (2007) S288-S294

6 Paper Comparison Maximum response of representative elastomer: Paper Experimental Setup Polymer Elastic energy density (J/cm 3 ) Pressure (MPa) Strain (%) Young s modulus (MPa) Electric field (V/µm) Dielectric constant (at 1 khz) 1 Silicone (Nusil CF ) Silicone (Dow Corning HS3) Polyurethane (Deerfield PT6100S) Silicone (Dow Corning Sylgard 186) Fluorosilicone (Dow Corning 730) Fluoroelastomer (Lauren L143HC) Isoprene Natural Rubber Latex Acrylic (3M VHB 4905) 3 Silicone (ShinEtsu KE441) Acrylonitrile butadiene rubber (NBR)

7 Comparison of dielectric elastomers with other actuator technologies: Actuator Type Conclusions Elastic energy density (J/cm 3 ) Electroactive Polymers are proper materials to solve the problems. Dielectric elastomers can generate more strain and force than many of the competing technologies. Their properties in this regard are similar to those of natural animal muscle hence the moniker artificial muscles. Specific elastic energy density (J/g ) Maximum Pressure (MPa) Maximum Strain (%) Dielectric Elastomer Silicone Dielectric Elastomer Polyurethane Electromagnetic (Voice Coil) Piezoelectric Ceramic Shape memory alloy (TiNi) >100 >15 >200 >5 Thermal (expansion) Natural muscle (human skeletal) >40

8 Comments & Critics Bidirectional actuation and compliance controllability are the most importance characteristic 4 typical states of human muscles: forward, backward, highly compliant, & highly stiff importance in robotic application. All papers use planar and cylindrical actuator limited application because of their dimensional characteristics, scalability, and adaptability need a study on co-materials which possible to scaled to small forms of many geometric dispositions and shapes fiber?

9 Thanks for your attention