Pneumatic valves in folded 2D and 3D fluidic devices made from plastic films and tapes

We present a rapid prototyping technique that expands elastomeric valving capabilities to devices made from thin materials such as plastic films and tapes. The time required from conception to full fabrication of functional devices is within a few hours. A key characteristic of this technology is that devices are thin (typically less than 0.5 mm in thickness), which allows for the fabrication of devices with many layers. This feature also permits folding of devices into 3D structures having fully functional valves. We illustrate this concept with the fabrication of a 25 mm-per-side cube whose walls contain microfluidic channels and valves. Control of liquid delivery through the faces of the cube is demonstrated with a chemotaxis experiment of C. elegans migrating within the enclosed volume of the cube as stimuli are delivered through the walls of the cube to the interior faces.