Integrated microfluidic systems for automatic glucose sensing and insulin injection

This paper presents a new microfluidic system capable of real-time measurement of glucose concentration and automatic insulin injection. The microfluidic system is composed of a microfluidic chip, a measurement and control circuit system, a compressed air source, and several electromagnetic valves to form a handheld system. The microfluidic chip is fabricated by using microfluidic techniques comprising of glucose sensing electrodes, a flow sensor and polydimethylsiloxane (PDMS)-based microfluidic structures such as micropumps, microvalves and microchannels. Commercially available needles are incorporated for continuous glucose monitoring and long-term insulin injection. The microfluidic system performs a variety of processes including blood sample collection, glucose concentration detection and injection of insulin. Compared with separate glucose monitoring and insulin injection platforms, the integrated system has a potential for on-line monitoring of glucose concentration and precise injection of proper doses of insulin. Even though this work is still in a preliminary stage towards practical applications, the developed microfluidic system has shown its potential to become a crucial tool for diabetes patients in the future. © 2006 Elsevier B.V. All rights reserved.