Adding millimeter-sized, rapidly prototyped robotic structures to microfluidic lab-on-a-chip devices

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.