1. Integrated Microfluidic Systems for Automatic Glucose Sensing and Insulin Injection 1 Chao-June Huang, 2 Chih-Hao Wang, 3 Yi-Hsin Chen, 3 Tse-Chuan Chou and, 1,2 Gwo-Bin Lee, 4 Xi-Zhang Lin, and 4 Ming-Hua Chen 1 Institute of Micro-Electro-Mechanical-System Engineering, 2 Department of Engineering Science, 3 Department of chemical engineering, 4 Department of Internal Medicine1 National Cheng Kung University MEMS design and Micro-fabrication Lab MML This study presents a new Microfluidic system capable of real-time glucose measurement and automatic insulin injection. The hand-held system used MEMS (Micro-Electro -Mechanical-Systems) techniques, which integrated micro-pumps, micro-valves, microchannels, needles and glucose sensing electrodes on a small chip. Glucose monitoring was performed in a process including blood sample collection, glucose concentration detection, and injection of insulin. Micro-pumps and micro valves were used to automate the whole process in this single chip. Preliminary data showed that the developed chip could successfully detect the glucose concentration and inject a specific amount of insulin through the needles. The developed system could be promising for on- line monitoring of human glucose concentration and precise injection of proper doses of insulin to maintain a stable blood glucose concentration. Abstract Design Schematic representation of the Microfluidic GSII (Glucose sensing and insulin injection) biochip (top-view). Fabrication 4.0 2 Plasma treatmnet and bonding 1.PR patterning 2.Ag deposition 3.Lift off 4.Au/Pt deposition 2.Photolithography 3.PDMS casting Bonding : Ag : Pt : Au : Glass : Silicon : PDMS : SU-8 Upper substrate Lower substrate 1.SU-8 spin coating A simplified fabrication process for the Microfluidic chip. PolyprroleGOD Working electrode :Pt Glucose injection H2O2H2O2 1. Pyrrole 0.05M & GOD 0.5mg/ml with 0.1M KCl. 2. Applied current 4.584uA for 130s on Pt. Results 3.Sink in P.B.S as blank phase. When electrode stable inject glucose. 4.GOD oxide glucose 5.Produce H 2 O 2 6.Sensing at 700mV vs. Ag/AgCl A simplified fabrication process for the working electrode. Output current of the glucose sensor at various glucose concentrations. 1 2 34 30 psi 25 psi 20 psi Pumping rate (μl/min) Frequency (Hz) The relationship between pumping rate and driving frequency for different working pressures. A series of photographs showing that insulin samples could be successfully injected using the developed micro-pumps through a stick needle. time (min) blood sugar concentration (mg/dL) Conclusions This study presented a MEMS-based Microfluidic system capable of performing the measurement of the glucose concentration and the insulin injection in an automatic and real-time fashion. Experimental results showed the glucose concentrations ranging from 1.61 to 30 mM can be detected. The sensitivity of the glucose sensor is measured to be 0.99 nA/mM The sensitivity is comparable to large-scale traditional detection system. The sample consumptions of the proposed chip device is less than 30μL Glucose response after injection of 0.3cc insulin in a mouse body 2006