Case Study: CEA LIST achieves optimized phase-change microactuators for miniature surgical robots with COMSOL Multiphysics

Actuation Technique for Miniature Robots Developed using Multiphysics Simulation

CEA LIST researchers (led by Christine Rotinat and Panagiotis Lazarou) set out to develop inexpensive, miniaturized phase-change actuators for minimally invasive surgical robots that deliver high force and displacement with low electrical consumption and safe operating temperatures. To model a paraffin–carbon black composite actuator based on Goldschmidtböing’s design and meet medical constraints (no high voltages or magnetic fields), they used Comsol’s COMSOL Multiphysics to simulate the coupled thermal, electrical and mechanical behavior.

Using Comsol, Lazarou built a nonlinear multiphysics model that accurately reproduced membrane deflection and temperature behavior, allowing rapid parameterization and optimization of actuator height, membrane thickness and composite conductivity. The simulation matched reference deflection data and predicted a maximum membrane deflection of about 36.1 µm with paraffin melting near ~42.8°C, enabling an optimized prototype design that promises low power use, compliance with medical limits, lower cost and reduced surgeon burden; the prototype was slated for completion and testing in 2014.

CEA LIST

Christine Rotinat

Researcher