Flexible polydimethylsiloxane pressure sensor with micro-pyramid structures and embedded silver nanowires: A novel application in urinary flow measurement.

Flexible pressure sensors are lightweight and highly sensitive, making them suitable for use in small portable devices to achieve precise measurements of tiny forces. This article introduces a low-cost and easy-fabrication strategy for piezoresistive flexible pressure sensors. By embedding silver nanowires into a polydimethylsiloxane layer with micro-pyramids on its surface, a flexible pressure sensor is created that can detect low pressure (17.3 Pa) with fast response (<20 ms) and high sensitivity (69.6 mA kPa⁻¹). Furthermore, the pressure sensor exhibits a sensitive and stable response to a small amount of water flowing on its surface. On this basis, the flexible pressure sensor is innovatively combined with a micro-rotor to fabricate a novel urinary flow-rate meter (uroflowmeter), and results from a simulated human urination experiment show that the uroflowmeter accurately captured all the essential shape characteristics that were present in the pump-simulated urination curves. Looking ahead, this research provides a new reference for using flexible pressure sensors in urinary flow-rate monitoring. ARTICLE HIGHLIGHTS: • A flexible pressure sensor is presented based on a micro-pyramid array and silver nanowires and with low detection limit, high sensitivity, and fast response. • The sensor responds accurately and stably to human pulse signals and rapidly changing cyclic loads. • The sensor can accurately and sensitively detect dynamic water flow passing over its upper surface, and the uroflowmeter designed using it has considerably high detection accuracy. [ABSTRACT FROM AUTHOR]