Congratulations to Tingting Mei and Wenchao for their article being accepted by Angelw Chem Int Ed!

Recently, Associate Professor Kai Xiao's research group published a research article titled "Bioinspired carbon nanotubes-based nanofluidic ionic transistor with ultrahigh switching capabilities for logic circuits" in the Angew. Chem. Int. Ed.. Research assistant Tingting Mei and doctoral student Wenchao Liu are co first authors, and the corresponding author is Associate Professor Kai Xiao.

Abstract: This paper is inspired by the membrane potential response mechanism of voltage gated ion channels (i.e. transistors of living organisms) and successfully prepared an ion based transistor based on transmembrane potential response. It achieved excellent performance of nanofluid transistors with ions as carriers and demonstrated its application and future development direction in signal processing of ion based circuits and neural mimicry.

The biggest difference between electronic devices and brain information processing mechanisms is that the human brain is an intelligent system that uses ions as information carriers with ultra-low energy consumption and ultra-high performance. Voltage-gated ion channels, also known as life's transistors, can precisely and selectively regulate ion transport and play important roles in maintaining important physiological activities and processing complex information in intelligent life. Inspired by this, ion transistors based on ions as information carriers have emerged (Figure 1). Exploring artificial devices that precisely control ion transport will promote the development of ultra-low energy information technology based on ion systems, and have broad application prospects for ion sensing, low-energy neuromorphic computing, and brain-machine interfacing.

The existing ion transistors are based on the double layer (EDL) effect of nanofluids and have successfully achieved the control of ion transport behavior by changing the surface charge density of the channel through gate voltage. However, to achieve signal processing similar to neurons, it is necessary to manufacture ion based transistors with high sensitivity, high switching ratio, and fast response. The reported switching ratio (~10) of ion based transistors still does not meet the requirements for constructing ion circuits, and the subthreshold swing (SS) that reflects the switching characteristics of transistors is often overlooked in the research of nanofluid transistors.

Figure 1 Schematic diagram of the working mechanism of transistors for living organisms and biomimetic ion based transistors

Inspired by the membrane potential responsive ion channel, this article constructs an ion based transistor based on transmembrane potential response by applying a single-sided gating voltage on the MXene membrane to form a transmembrane potential similar to that of a neuron cell membrane (Figure 1), achieving a high switching ratio of~2000. And the transition of ion based transistors from bipolar to unipolar was achieved by introducing asymmetric PET/MXene composite films. And the sub threshold swing is reduced to 560 mV/decade, reflecting more sensitive switching characteristics. By leveraging the excellent performance of ion transistors, ion based logic gates including "NOT gates", "NAND gates", and "OR gates" have been successfully constructed (Figure 2), achieving functions similar to neuronal dendritic signal integration. This provides a promising approach for the construction of more complex ion circuits in the future, achieving high parallel and low-energy ion based brain computing.

Figure 2 Construction of ion based logic circuit and neural mimicry signal processing

Link: https://doi.org/10.1002/anie.202401477