Hydrophilic Interfacing for Thermal Micro Assembly of Polymers (HITMAP)

This paper presents a simple approach to create microchannels in polydimethylsiloxane (PDMS) using basic hydrophobic–hydrophilic interactions of polymers. During polymerization, low molecular weight hydrophobic chains of PDMS expel hydrophilic moieties. This phenomenon has been used to create microchannels in PDMS. The process is simple, systematic, flexible in design, easy to implement, rapid, inexpensive and does not require lithography. Fabrication of microchannels in PDMS can be carried out using bench-top tools without the aid of any special facilities or equipment. With directed thermal polymerization over the hot plate, the expulsion of hydrophilic materials creates microchannels along the path traveled by particles. The approach is sensitive to the polymer viscosity, temperature profile and the surface chemistry of the particles. This work can have important implications in reducing the cost and time for prototyping polymer based applications in separation science, cell behavior studies, catalytic membranes and hydrogen storage. The membranes are characterized for electrical continuity and charge effects on conductivity.