Fully Gravure-Printed Flexible Full Adder Using SWNT-Based TFTs

A single-walled carbon nanotube (SWNT)-based 1-b full-adder circuit was realized on flexible plastic substrates through an all gravure printing process by minimizing intertransistor process variation and leakage current between crossing interconnects. The circuit comprised 27 printed SWNT thin-film transistors, with a variation of up to only ±25% in electrical characteristics among them. Furthermore, the circuit showed a maximum propagation delay of 13.7 ms, with a 50-Hz input signal, and a supply voltage of -20 V. The process could be used for low-cost flexible arithmetic logic units in a variety of applications.