Ultrathin and Wearable Microtubular Epidermal Sensor for Real-Time Physiological Pulse Monitoring

A flexible, stretchable, soft, and ultrathin wearable microtubular sensor that is highly sensitive to mechanical perturbations is developed. The sensor comprises a unique architecture consisting of a liquid-state conductive element core within a soft silicone elastomer microtube. The microtubular sensor can distinguish forces as small as 5 mN and possesses a high force sensitivity of 68 N-1. The microtubular sensor occupies a tiny footprint of 120 mu m in diameter, approximately the cross-section of a strand of hair. Superior sensing capabilities of the sensor are reported to detect perturbations from pulsatile air flows and demonstrate its applicability in continuous and imperceptible real-time monitoring of arterial pulse waves.