A constant flow rate pulse-driven microfluidic patch-pump for transdermal drug delivery

Syringes and tethered infusion pumps with needles and cannulae have been the standard method for delivering liquid pharmaceuticals across the skin barrier for decades. But these delivery methods have limitations including painful cannula insertion and interference with daily activity, which can lead to non-adherence to prescribed liquid infusion regimens. To address these limitations, we are developing pulse-driven microfluidic patch-pumps inspired by principles of insect respiration that are extremely low-profile compared to standard wearable infusion pumps because they do not require a motor or batteries. The devices can be integrated with microneedle arrays to mitigate needle insertion pain. Previously, we developed patch-pump devices whose flow rate increased or decreased with the actuating heart rate, the latter of which is ideal for insulin delivery. We have recently developed devices whose flow rate does vary with heart rate. By testing the devices with a pressurized air-driven pulse simulator, we identified devices that generate constant flow rates ranging from 0.2 mL/hr, suitable for the delivery of insulin, to 10 mL/hr, suitable for the delivery of chemotherapies and analgesics.