Development of low flow rate disposable electrolysis pump for subepidermal microperfusion

An electrolysis pump was developed for wearable microperfusion system. In our previous work, minimally invasive microperfusion needle which collects biological substances from subepidermal tissue had been developed. The pump for perfusate perfusion of this microperfusion system requires low flow rate, continuous flow, low power consumption and disposability. Electrolysis pump is relatively simple structure and requires low power consumption. Thus, electrolysis pump is suitable for disposable device. Fabricated pump consists of an electrolyte chamber which contains interdigitated array electrodes, a discharge liquid chamber and a Parylene corrugated membrane between the two chambers. The electrolyte chamber is filled with deionized (DI) water. The gases (hydrogen and oxygen) are produced in electrolyte chamber and the liquid is discharged by pushing the corrugated membrane. The fabricated pump had enough function to discharge the discharge liquid at a flow late of less than 5 μl/min for more than 120 minutes. When this pump is used in wearable system, the pump is used in various positions. Hydrogel was added to electrolyte to reduce influence of position changes. This pump had enough function to discharge liquid in required condition at up-side down condition.