Robust physiological signal monitoring by a flexible piezoresistive sensor microstructured with filamentating laser pulses

Abstract

Flexible pressure sensors are promising for biomedical diagnosis and health monitoring, but most of such sensors meet with problems of one kind or another, such as counterfeit sensitivity, poor durability, expensive fabrication cost and trade-off between sensitivity and sensing range. Herein, a high-performance flexible pressure sensor microstructured with femtosecond filamentating pulses is assembled to realize robust physiological signal monitoring. The sensing mechanism is based on the change of contact resistance between the patterned silver conductive ink thin layer and the laser filament-microstructured polydimethylsiloxane film coated with single-walled carbon nanotubes. The sensor exhibits a maximum sensitivity of 0.266 kPa−1, a broad range of up to 160 kPa and an excellent stability. Benefiting from the aforementioned advantages, the sensor is used with success to detect a variety of human physiological signals, such as real-time artery pulse and throat muscle movement. Moreover, with the assistance of principle component analysis algorithm, it is demonstrated that the sensor can unambiguously distinguish different phonations, making it high potential for application in physiological analysis systems.