Multilayer track‐etched membrane‐based electroosmotic pump for drug delivery

Herein, we report an electroosmotic pump (EOP) based on a multilayer track‐etched polycarbonate (PC) membrane. A remarkable increase of maximum backpressure (198.2–2400 mmH2O) of a fundamental pump unit was obtained at 0.8 mA, when the number of PC membranes was increased from 1 to 10. Meanwhile, the corresponding flow rate was increased from 80.3 to 111.7 µL/min. Furthermore, multiple pump units were assembled in series to obtain a multistage EOP. For a three‐stage EOP (EOP‐3), the operating voltage and power can be decreased significantly by 52%–72% under different driving currents, with a minimum power of 26.7 µW. Thus, EOP‐3 can run stably over 35 h at a pulse current of 0.1 mA without the generation of gas bubbles. The pump was further integrated into a miniature device, which was successfully used to decrease the blood glucose level of diabetic rats by subcutaneous delivery of fast‐acting insulin. This work brings a facile and efficient strategy to enhance the backpressure and lower the operating voltage and power of EOPs, which may find promising applications in drug delivery.