Fabrication of optically patternable nanocomposite layers for smart polymer structure applications

We are reporting the development of a conductive nanocomposite for sensing applications. Unlike the previously reported research, our process flow allows for fabrication of nanocomposite structures that can be patterned using typical lithography techniques for fine features. This advantage lets us fabricate embedded micro-sensors within a multi-layer polymer structure. In order to demonstrate the principle, different SU8 structures were impregnated with carbon nanotubes and studied. These nanocomposite structures behave in a manner, resembling results of percolation theory. It is also demonstrated that filler concentration strongly affects the response of the fabricated nanocomposite structures to strain with measured gauge factors ranging from 1.5 to more than 15. The fabrication process is explained in detail and our study is supported by modeling of a random carbon nanotubes network based on our own simulation code. This technology will be used for fabrication of low-cost all-polymer structures with embedded sensors and actuators.