Universal In Situ Flowrate Monitoring for Piezoelectric Microfluidics via Triboelectric Self-Sensing

Conventional flowrate monitoring methods for piezoelectric micropumps suffer from limited integration capability, contamination risks, and laboratory dependence. Here, we propose a universal in situ flowrate monitoring method through triboelectric sensing that overcomes these fundamental limitations. By integrating a triboelectric sensor directly within the piezoelectric micropump cavity, we achieve real-time flowrate monitoring by detecting the piezoelectric vibrator deformation through triboelectric signals. Experimental validation across three distinct micropump architectures demonstrates the remarkable universality of two flowrate monitoring methods (voltage amplitude and frequency pulse), achieving linear fitting coefficients exceeding 0.99 and average monitoring errors below 2.49%. We further develop a microcomputer-driven system for drug injection applications, achieving flowrates up to 2.2 mL/min with maintained monitoring accuracy of 2.298%. This work establishes a paradigm for fully integrated microfluidic devices and paves the way for intelligent drug delivery systems.