Rupam Mandal is a Postdoctoral Researcher at National Institute of Materials Science, Japan. He earned his Ph.D. in Physics from Homi Bhaba National Institute in Mumbai, India. His research focuses on solid state ionic devices for neuromorphic applications, with a particular emphasis on memristors and ion-gated transistors.

The human brain efficiently processes complex spatiotemporal information through distributed ionic dynamics. Ion-gated transistors have emerged to be promising neuromorphic devices because of a very similar ion dynamics [1,2]. Here, we propose a multiterminal proton-gated oxide transistor employing electron beam lithographically patterned Nafion as a proton-conducting electrolyte and a sputtered WO₃ channel [3]. Migration of protons through Nafion and their incorporation into the WO₃ channel under electrical stimuli enables large channel conductance modulation (as high as ~103). Moreover, multiple independently controlled gate terminals provide spatially distributed inputs, allowing the devices to perform spatial and temporal integration, coincidence detection, and dendritic discriminability within a single transistor. The devices further demonstrate real-time spatiotemporal processing tasks like acoustic sound localization by constructing a simple artificial neural network. This work establishes a compact low-power hardware platform for spatiotemporal computing and next-generation edge artificial intelligence.

1. Guansong Qiu et al., Mater. Horiz. 13, 7345–7366 (2026) DOI: 10.1039/d6mh00693k
2. Yongli He et al., Adv. Mater. 31, 1900903 (2019) DOI: 10.1002/adma.201900903
3. Himadri Nandan Mohanty et al., ACS Appl. Mater. Interfaces. 00, 19279−19289 (2023) DOI: 10.1021/acsami.3c00756