Design of a Valveless Micro-Pump for Variable Rate of Insulin Delivery

Objectives: Unlike conventional micro-pumps which have valves that fail as they keep flapping twice during each pumping cycle and a separate micro-needle array, through which drug is injected. The design here uses a micro-pump without moving valves and with the micro-needles integrated with the micro-pump itself. Method/Statistical Analysis: The dimensions for the micro-pump and the micro-needles are chosen based on the physical characteristics of the fluid that needs to be pumped (in this case insulin density, viscosity, size of the particles in the fluid etc). The model is constructed and simulated using COMSOL multi-physics software. Findings: The model is simulated to check the volume of liquid pumped during each cycle and to see if the model constructed remains stable when potential is applied to the actuating membrane. The simulation results showed that the micro-pump model constructed is stable under various levels of applied potential (+200V to -200V), results of which are presented in the following sections. It was also observed that the dead volume of fluid that is left in the pumping chamber is less as compared to the conventional model. Application/Improvement: This micro-pump was designed especially for insulin delivery. The actuation method being piezo-electric, the volume of fluid pumped can be altered by varying the frequency of the applied potential or the amplitude of the applied voltage. This model can still be improved if it can be integrated with a glucose sensor. Based on the level of the glucose measured the insulin to be delivered can be altered.