Dielectric Elastomer Actuators for Microfluidics
One of the goals of microfluidics is to bring a whole laboratory processing chain on a few square centimeters, Lab-On-Chips (LOC). But current LOCs require many heavy and power-consuming off-chip controls like pneumatics, pumps and valves, which keep the small chip bound to the lab. Miniaturized Dielectric Elastomer Actuators (DEA) are excellent candidates to make LOC truly portable, since they combine electrical actuation, large stroke volumes and high output forces. We report on the use of zipping actuation applied to DEAs for an array of 3 mm-size chambers, forming a peristaltic pump. Unlike the traditional actuation mechanism of DEAs that squeezes an elastomer between 2 compliant electrodes, zipping DEAs use electrostatic attraction between a compliant electrode and a rigid one (the sloped chamber walls). A zipping analytical model was developed to predict the actuator's behavior and help for the design (chamber dimensions, silicone type and thickness.). Three chambers connected by an embedded channel were wet-etched into a silicon wafer and subsequently covered by a gold-implanted silicone membrane. Static deflections up to 300 micrometers were measured on chambers with square openings from 1.8 to 2.6 mm on a side in very good agreement with the model, but breakdown occurs before predicted. The design parameters are varied to assess the model and determine the most relevant factors to achieve a fully zipped depth of 525 micrometers.
Record created on 2016-06-19, modified on 2016-08-09