Humidity Sensor Synaptic Device Based on Bilayer p–n Heterojunction Transistors for Maintaining Humidity Homeostasis

Emerging artificial synaptic devices, endowed with the ability to process electronic signals using neuromorphic functions, mimic the operation of biological nervous systems. In this work, a humidity-sensitive artificial synaptic device is fabricated, which not only detects humidity but also generates a remarkable synaptic signal simultaneously. The device effectively attains a synaptic current response in diverse humidity environments due to the utilization of a humidity-sensitive CMC-Na+GO/DCNBT-IDT bilayer p–n heterojunction transistor. With an increase in humidity, the concentrations of water molecules, hydroxyl groups, and protons in the medium increase, resulting in a more efficient ion transport effect that enhances the device conductivity. Ultimately, the fabricated synaptic device was utilized to achieve a negative feedback system for regulating humidity homeostasis.