Skin-inspired in-sensor encoding of strain vector using tunable quantum geometry

TL;DR

This paper introduces a skin-inspired sensor that encodes complex strain vectors using the quantum geometric properties of Td-WTe2, enabling high-dimensional tactile sensing in a single device.

Contribution

It demonstrates a novel method to directly encode high-dimensional strain information via quantum geometry effects in a topological semimetal, advancing flexible bio-inspired electronics.

Findings

Robust nonlinear Hall responses to strain magnitude and direction

Quantum geometry underpins strain-dependent Hall signals

Single-device encoding of complex strain patterns

Abstract

Human skin provides crucial tactile feedback, allowing us to skillfully perceive various objects by sensing and encoding complex deformations through multiple parameters in each tactile receptor. However, replicating this high-dimensional tactile perception with conventional materials' electronic properties remains a daunting challenge. Here, we present a skin-inspired method to encode strain vectors directly within a sensor. This is achieved by leveraging the strain-tunable quantum properties of electronic bands in the van der Waals topological semimetal Td -WTe2. We observe robust and independent responses from the second-order and third-order nonlinear Hall signals in Td -WTe2 when subjected to variations in both the magnitude and direction of strain. Through rigorous temperature-dependent measurements and scaling law analysis, we establish that these strain responses primarily stem from quantum geometry-related phenomena, including the Berry curvature and Berry-connection polarizability tensor. Furthermore, our study demonstrates that the strain-dependent nonlinear Hall signals can efficiently encode high-dimensional strain information using a single device. This capability enables accurate and comprehensive sensing of complex strain patterns in the embossed character "NJU". Our findings highlight the promising application of topological quantum materials in advancing next-generation, bio-inspired flexible electronics.