Published online by Cambridge University Press: 26 February 2011
The small volume of sample and fast response time are the primary features of micro fluidic system. It is essential for expensive samples. Microvalve is a key to regulate the flow movement component in an integrated microfluidic system. The working principle of conventional microvalves relies on its mechanical or electromagnetic properties. These valves are neither biocompatible nor are suitable for bioassays. Stimuli-response hydrogels whose properties of efficient mode of energy conversion (chemical to mechanical), excellent biocompatibility and the combination of multiple function (sensing and actuation) have become the leading candidate as engineered microscale components. In this paper, we study the feasibility of thermo-sensitive hydrogel as a valve on the microchip. A metal resistor was used as the temperature regulator. The results show that the miniaturization fabrication of the hydrogel depends on many factors like the volume of the hydrogel (the size of the valve), the vacuum condition (the evaporation rate) and the deposition substrate. The degree of swelling and deswelling of the hydrogel valve depends on the size of the hydrogel. This micro fluidic system is regulated by temperature change of the aqueous solution. The integration with other fluidic component is crucial for practical application.