Fabrication of patterned carbon nanotube (CNT) / elastomer bilayer material and its utilization as force sensors

This paper reports a room-temperature fabrication process for production of localized regions of highly-loaded carbon nanotube (CNT) networks within the surface layers of polydimethylsiloxane (PDMS). These bilayer micro-structures are formed by electrophoretic deposition (EPD) of CNTs into a patterned mold, followed by a transfer-micromolding step. The fabricated CNTs/PDMS bilayer exhibits flexibility, maintains a high local CNT concentration while eliminating issues associated with dispersion and bulk rheology, and preserves the spatial orientation of the original EPD pattern. The use of the material is demonstrated in piezoresistive strain and transverse compression force testing, and is characterized for sensor applications.