Bidirectional Haptic Feedback for Prostheses via Flexible Sensing and Transcutaneous Electrical Stimulation

ABSTRACT Upper‐limb amputation disrupts natural somatosensory pathways and impairs motor control, increasing reliance on visual feedback during prosthesis operation and reducing intuitiveness and embodiment. Although haptic feedback can improve controllability, most commercial myoelectric prostheses still lack effective closed‐loop feedback. Here, we present a flexible Bidirectional Haptic Feedback System (BHFS) integrating triboelectric multidimensional tactile sensing with multichannel transcutaneous electrical stimulation (TES). The customized Triboelectric Flexible Tactile Sensor (TFT‐Sensor), featuring a strontium titanate (SrTiO 3 )‐modified triboelectric layer with a pyramid microstructure, achieves a 75% increase in open‐circuit voltage compared to the baseline, enabling zero‐power sensing of pressure, shear force, and surface texture. A flexible electrode armband driven by a multichannel electrical stimulator delivers spatiotemporally encoded electrical patterns through closed‐loop mapping algorithms, providing intuitive multidimensional somatosensory feedback. In simulated prosthetic‐hand experiments under audiovisual deprivation, subjects successfully adjusted grip force in real time, maintained stable grasping, and distinguished different surface textures. By establishing a closed‐loop “sensing‐mapping‐stimulation” framework, the proposed system offers a promising strategy for restoring naturalistic somatosensation in prosthetic devices and advancing rehabilitation engineering and human–machine interfaces.