This paper describes a rapid prototyping method to add robotic functionality to microfluidic devices using existing equipment, materials, and methods already employed in photolithography. Details on the fabrication as well as basic design and analyses methods are given. These techniques are then employed to fabricate an example structure that is subsequently integrated with a microfluidic channel. The eventual purpose of this example structure would be to serve as an interface between a microfluidic device and its environment, using a brush-like structure to sweep cells into the channel, which could then be delivered to another microfluidic system for analyses of the cells. The resulting brush-like structure fits within a 6 mm times 4 mm times 2 mm volume and can be further miniaturized. The alteration of compressed air and vacuum modulated by pneumatic solenoid valves is used to push and pull a plunger/rod system that actuates the device. The delivery of the pressurized air and vacuum is accomplished through flexible 500 mum-diameter tubing to the plunger/rod system but future work would involve completely containing the actuation on a chip-size device.

This paper presents a new biphasic electrofluidic rotary actuator relying on electrochemical mechanisms. Gas (H2and O2) is generated at two platinum (Pt) electrodes, immersed in an electrolytic solution, when a low voltage, V, is applied to them. The generated gas pressurizes a closed elastomeric chamber, that deforms under the action of the applied pressure. The chamber is shaped so that no structural failure occurs and the desired output motion is produced, without any need for additional mechanical means such as motion converters. Simple thermodynamic considerations allow estimating the electromechanical coupling factors for the most common external loads.