Flexible and low-voltage ITO synaptic transistors for biotic tactile sensing

Artificial intelligence technology has fueled the requirement for flexible hardware. Although flexible electronic devices have become promising candidates in recent years, they inevitably face problems like performance degradation caused by deformation. In this paper, we report a stable performance and flexible indium tin oxide synaptic transistor with an ultralow back-sweep subthreshold swing of 28.52 mV/dec, which is ascribed to the positive charge trapping/de-trapping effect introduced by a naturally oxidized Al2O3 layer. Even after bending 1 × 103 times, the flexible artificial synapse shows stable electrical performance without evident attenuation. Furthermore, the synaptic transistor exhibits good compatibility with an external thin-film pressure sensor, and their combination empowers the device to realize tactile sensing, which can achieve the function of Braille code recognition. Evidently, the reported flexible synaptic transistor demonstrates its potential for artificial perception processing.