Flexible Monolithic 3D-Integrated Self-Powered Tactile Sensing Array Based on Holey MXene Paste
Mengjie Wang, Chen Chen, Yuhang Zhang, Yanan Ma, Lili Xu, Dandan Wu, Bowen Gao, Aoyun Song, Wen Li, Yongfa Cheng, Siliang Wang, Yang Yue
Abstract
Flexible electronics face critical challenges in achieving monolithic three-dimensional (3D) integration, including material compatibility, structural stability, and scalable fabrication methods. Inspired by the tactile sensing mechanism of the human skin, we have developed a flexible monolithic 3D-integrated tactile sensing system based on a holey MXene paste, where each vertical one-body unit simultaneously functions as a microsupercapacitor and pressure sensor. The in-plane mesopores of MXene significantly improve ion accessibility, mitigate the self-stacking of nanosheets, and allow the holey MXene to multifunctionally act as a sensing material, an active electrode, and a conductive interconnect, thus drastically reducing the interface mismatch and enhancing the mechanical robustness. Furthermore, we fabricate a large-scale device using a blade-coating and stamping method, which demonstrates excellent mechanical flexibility, low-power consumption, rapid response, and stable long-term operation. As a proof-of-concept application, we integrate our sensing array into a smart access control system, leveraging deep learning to accurately identify users based on their unique pressing behaviors. This study provides a promising approach for designing highly integrated, intelligent, and flexible electronic systems for advanced human-computer interactions and personalized electronics.