Design, fabrication and characterization of a conducting PDMS for microheaters and temperature sensors

In this paper, we present the design and fabrication procedure of a conducting polydimethylsiloxane (PDMS) and then evaluate its potential uses for heating and temperature sensing. The conducting PDMS was made up of a mixture of a PDMS prepolymer and metallic powder. Depending on purpose, i.e. heater or sensor, different weight ratios of the powder and geometric shapes were considered. Characterization of both the microheaters and the temperature sensors includes stability, repeatability, durability and time response. The results suggest that the microheater is feasible for constantly heating at a fixed temperature instead of running thermal cycles. The optimal heating range was estimated below 100 °C under the current setup and a power consumption of 210 ± 12 mW was needed for 92 °C. Hysteresis and time lag were observed in the temperature sensor. Accordingly, the sensor is recommended to be used for long-term monitoring instead of rapid temperature detections.

[1]  Francis H. Ku,et al.  Dispersion of carbon black in a continuous phase: Electrical, rheological, and morphological studies , 2002 .

[2]  Pin-Chuan Chen,et al.  Rapid PCR in a continuous flow device. , 2004, Lab on a chip.

[3]  M. Narkis,et al.  Sensing of liquids by electrically conductive immiscible polypropylene/thermoplastic polyurethane blends containing carbon black , 2003 .

[4]  Pasi Kallio,et al.  PDMS and its Suitability for Analytical Microfluidic Devices , 2006, 2006 International Conference of the IEEE Engineering in Medicine and Biology Society.

[5]  John A. Rogers,et al.  Low-cost, low-loss microlens arrays fabricated by soft-lithography replication process , 2003 .

[6]  S. Quake,et al.  Monolithic microfabricated valves and pumps by multilayer soft lithography. , 2000, Science.

[7]  W. Wen,et al.  Microheaters fabricated from a conducting composite , 2006 .

[8]  P. Sheng,et al.  Characterizing and Patterning of PDMS‐Based Conducting Composites , 2007 .

[9]  George M. Whitesides,et al.  Microsolidics: Fabrication of Three‐Dimensional Metallic Microstructures in Poly(dimethylsiloxane) , 2007 .

[10]  T. N. Vijaykumar,et al.  POLYDIMETHYLSILOXANE (PDMS) PERISTALTIC PUMP CHARACTERIZATION FOR PROGRAMMABLE LAB-ON-A-CHIP APPLICATIONS , 2008 .

[11]  Matthew O'Donnell,et al.  High-frequency ultrasound array element using thermoelastic expansion in an elastomeric film , 2001 .

[12]  William Thies,et al.  Digital microfluidics using soft lithography. , 2006, Lab on a chip.

[13]  William H. Grover,et al.  Development and multiplexed control of latching pneumatic valves using microfluidic logical structures. , 2006, Lab on a chip.

[14]  N. Tsubokawa,et al.  Novel gas sensor from polymer-grafted carbon black: Vapor response of electric resistance of conducting composites prepared from poly(ethylene-block-ethylene oxide)-grafted carbon black , 2000 .

[15]  Rashid Bashir,et al.  Reliable fabrication method of transferable micron scale metal pattern for poly(dimethylsiloxane) metallization. , 2006, Lab on a chip.

[16]  R. Mashelkar,et al.  A mechanistic interpretation of the zero order release from pendent chain-linked glassy and swollen hydrogels , 1990 .