A Bioinspired Artificial Gustatory Neuron for a Neuromorphic Based Electronic Tongue

• DOI: 10.1021/acs.nanolett.2c01107
• Publication Date: 2022-06-23T16:51:33Z
• Authors: Joon-Kyu Han; Sang-Chan Park; Ji-Man Yu; Jae-Hyuk Ahn; Yang-Kyu Choi
• Keywords: Neurons; Semiconductors; Sodium; Oxides; Neural Networks, Computer; 02 engineering and technology; Electronic Nose; 0210 nano-technology

A novel biomimicked neuromorphic sensor for an energy efficient and highly scalable electronic tongue (E-tongue) is demonstrated with a metal-oxide-semiconductor field-effect transistor (MOSFET). By mimicking a biological gustatory neuron, the proposed E-tongue can simultaneously detect ion concentrations of chemicals on an extended gate and encode spike signals on the MOSFET, which acts as an input neuron in a spiking neural network (SNN). Such in-sensor neuromorphic functioning can reduce the energy and area consumption of the conventional E-tongue hardware. pH-sensitive and sodium-sensitive artificial gustatory neurons are implemented by using two different sensing materials: Al2O3 for pH sensing and sodium ionophore X for sodium ion sensing. In addition, a sensitivity control function inspired by the biological sensory neuron is demonstrated. After the unit device characterization of the artificial gustatory neuron, a fully hardware-based E-tongue that can classify two distinct liquids is demonstrated to show a practical application of the artificial gustatory neurons.