Shape-Deformable and Locomotive MXene (Ti3C2Tx)-Encapsulated Magnetic Liquid Metal for 3D-Motion-Adaptive Synapses

Abstract

Owing to their unique surface chemistry, room-temperature pseudoliquidity, and high electrical conductivity, gallium-based liquid metals (LMs) exhibit multifunctionality. To grant deformable and self-flowing characteristics to LMs, magnetic particles are incorporated for precisely controlling the LM motion and shape deformability. However, LM surface-adhesion and corrosivity hinders the integration of LMs into complex circuits and devices owing to potential alloying with other metals and contamination of their surroundings. In this study, a highly conductive Ti3C2Tx (MXene)-encapsulated magnetic LM (MX-MLM) is developed using a feasible fabrication method. The MX-MLM comprises magnetic particles suspended within its core and self-assembled MXene flakes on the surface to maintain the nonwettability and high electrical conductivity of a liquid droplet. The noncorrosivity and increased magnetism of the MX-MLM enable nonstick magnetic-field-induced locomotion and shape deformation on various surfaces including metals, oxides, and polymers. Furthermore, the MX-MLM exhibits recyclability and magnetic-field-induced self-healing. To demonstrate its functionality, the MX-MLM is employed as a magnetointeractive, shape-deformable, and locomotive top gate electrode in a transistor fabricated using a ferroelectric polymer gate insulator. The device exhibits excellent magnetointeractive synaptic capability for detecting and learning 3D path information.