Ultrasensitive low power-consuming strain sensor based on complementary inverter composed of organic p-and n-channels

The use of low-strain sensors based on complementary inverters for the detection of tensile strain has been verified. Complementary inverter-type gauge circuits are comprised of a strain-sensitive bendable C₂₆H₁₆N₂(heptazole)-based organic field-effect transistor (OFET) and a relatively strain-insensitive N,N′-ditridecyl-perylene-3,4:9,10-tetracarboxylic diimide-C13(PTCDI-C13)-based one, as p-and n-channels, respectively. This study complementary circuit showed a voltage gain of more than 10 and a relatively low static current (below 0.2 nA) at a supplied voltage of 5 V, without strain application. Using the elastic and reversible response to the tensile strain in the heptazole p-channel, the complementary inverter-type gauge circuit enabled us to achieve a high gauge factor of 90% and to measure an extremely low strain level of 0.02% under subnanowatt power dissipation conditions during the strain-sensing operation. This ultrasensitive and low power-consuming strain gauge could be highly beneficial for portable and large-area strain sensors, one of the most critical components of mobile applications.