Dual-mode flexible physiological mechano-sensor leveraging microfluidic deformation induced liquid-solid interfacial capacitance and triboelectricity

Real-time monitoring of physiological signals on human skin surfaces represents a core functionality of wearable medical devices. Although microfluidic technology has garnered considerable attention in biochemical sensing (e.g., sweat, glucose), its potential for physiological mechanosensing remains largely untapped, hindering multi-parameter integration in one platform. Herein, we introduce a dual-mode flexible physiological force sensor based on microfluidic deformation. This sensor integrates capacitive and triboelectric mechanisms, overcoming single-mode sensing limitations. The liquid droplet serves a dual role: it acts as a deformable electrode, forming a capacitive structure with the bottom electrode for static force detection, while functioning as a triboelectric component interacting with the PDMS tribo-layer to capture dynamic force signals. Through parameter optimization, the sensor achieves synergistic optimization between sensitivity (4.078 kPa⁻¹) and detection range, with dynamic response of 21 ms. Experimental validation demonstrated 168-hours stable underwater pulse monitoring, confirming its biomedical potential for mechanical-biochemical signal fusion and holistic physiological analysis.