Skin preparation–free, stretchable microneedle adhesive patches for reliable electrophysiological sensing and exoskeleton robot control

Abstract

High-fidelity and comfortable recording of electrophysiological (EP) signals with on-the-fly setup is essential for health care and human-machine interfaces (HMIs). Microneedle electrodes allow direct access to the epidermis and eliminate time-consuming skin preparation. However, existing microneedle electrodes lack elasticity and reliability required for robust skin interfacing, thereby making long-term, high-quality EP sensing challenging during body movement. Here, we introduce a stretchable microneedle adhesive patch (SNAP) providing excellent skin penetrability and a robust electromechanical skin interface for prolonged and reliable EP monitoring under varying skin conditions. Results demonstrate that the SNAP can substantially reduce skin contact impedance under skin contamination and enhance wearing comfort during motion, outperforming gel and flexible microneedle electrodes. Our wireless SNAP demonstration for exoskeleton robot control shows its potential for highly reliable HMIs, even under time-dynamic skin conditions. We envision that the SNAP will open new opportunities for wearable EP sensing and its real-world applications in HMIs.

Self-Adhesive, Self-Healing, and Water-Soluble Polymeric Dry Electrodes for Robust Physiological Signal Monitoring

“…32−34 For example, Kim et al demonstrated a stretchable microneedle adhesive patch, characterized by excellent skin permeability and a robust electromechanical skin interface. 35 Zhang et al presented the sensors, adhering to the hairy scalp by generating negative pressure within their conical microstructures. 36 within seconds.…”

“…Dry electrodes, devoid of the necessity for electrolyte gels, could circumvent the costs and intricacies that are caused by the periodic liquid replenishment in wet electrodes and also could alleviate the skin sensitivity induced by prolonged usage. Dry electrodes usually use nanomaterials such as carbon nanoparticles, graphene, and metal nanoparticles as conductive materials and add matrix materials like polymer, rubber, or silicone to enhance structural strength, forming conductive polymer composite electrodes. − For example, Kim et al demonstrated a stretchable microneedle adhesive patch, characterized by excellent skin permeability and a robust electromechanical skin interface . Zhang et al presented the sensors, adhering to the hairy scalp by generating negative pressure within their conical microstructures .…”