Oxide Thin-Film Electronics on Carbon Fiber Reinforced Polymer Composite

In this letter, the direct fabrication of amorphous indium-gallium-zinc-oxide thin-film transistors (TFTs) and circuits on a commercial carbon fiber reinforced polymer (CFRP) substrate is demonstrated. The CFRP is encapsulated with a
$\approx 10.6-\mu \text{m}$
-thick resin layer, although the surface roughness and temperature sensitivity of the substrate are not ideal for the fabrication of electronic devices, we present depletion mode TFTs exhibiting a field effect mobility of
$18.3~\text {cm}^{2}\text {V}^{-1}s^{-1}$
, and a common source amplifier, providing a voltage gain of 8 dB and a −3 dB cutoff frequency of 11.5 kHz. The amplifier does not require any input bias voltage and can, hence, be directly used to condition signals originating from various transducers, e.g., piezoelectric strain sensors used to monitor the structural integrity of CFRP elements. This opens the way to the fabrication of smart mechanical CFRP parts with integrated structural integrity monitoring systems.