Direct Writing of Cu-based Micro-temperature Sensors onto Glass and Poly(dimethylsiloxane) Substrates Using Femtosecond Laser Reductive Patterning of CuO Nanoparticles

Abstract

Micro-temperature sensors are fabricated directly onto glass and flexible Poly(dimethylsiloxane) (PDMS) substrates using femtosecond laser reductive patterning of CuO nanoparticles. Cu/Cu2O composite micro-temperature sensors that consist of Cu2O-rich sensing parts and Cu-rich electrodes are fabricated on glass substrates by controlling the reduction degree of CuO nanoparticles to Cu and Cu2O. The sensor on the glass substrates has a large negative temperature coefficient of resistance. The conductive micropatterns fabricated on the PDMS substrates are Cu-rich only micropatterns. Cu-rich micro-temperature sensors are formed on the PDMS substrates, which exhibit a positive temperature coefficient of resistance. The temperature dependences of the sensors’ resistance are consistent with those of Cu and Cu2O. This selectively reductive method for patterning functional materials is useful for fabricating microdevices.