Feasibility Studies on Nafion Membrane Actuated Micropump Integrated With Hollow Microneedles for Insulin Delivery Device

A paradigm shift in conventional insulin delivery techniques is required to provide diabetic patients with painless, precise, safe and accurate insulin delivery solutions. Large size insulin molecules can be pushed through human skin layers by a micropump through hollow microneedles which provide a painless interphase to human skin. Ionic polymer metal composite membranes offer great advantages in micropump actuation due to their large deflections at relatively low actuation voltages. This makes them suitable to be implemented in insulin delivery devices. This article presents a novel integrated design of an insulin delivery device (IDD) consisting of a hollow microneedle array, drug reservoir and Nafion membrane actuation based micropump. To test the feasibility of the gold coated Nafion 115 membrane, it is utilized in the conventional circular as well as modified geometry having greater degree of freedom of movement by introducing cuts in membrane in a micropump structure and then implemented in the proposed IDD structure. The IDD achieves a DI water flowrate of $47.2\mu $ L/min and Insulin flowrate of $44.8\mu $ L/min for membrane with modified geometry which is higher as compared to the conventional membrane design. The device can achieve tunable insulin flowrate in the range of 20-45 $\mu $ L/min by varying the frequency (0.1-0.5Hz) and voltage (3-6V) paving way for its commercialization for painless insulin delivery. [2019-0109]