Microfluidic components such as microvalve,microchambers,and micropillars,are essential to control "microenvironments" on a chip and achieve precise bioanalysis.In this presentation,we would like to show two novel microfluidic components,a temperature-driven self-actuated microvalve [1] and a loop microchannel with micropillar array,for bioanalytical applications.Thermo-pneumatic valves and pumps have been developed using temperature-sensitive materials so that the valves are actuated effectively by temperature.These temperature-sensitive materials could be adopted in microreactors using thermal activation for reactions to close the microreactors automatically,but putting a temperature-sensitive material into a microchannel involves cumbersome fabrication procedures.In recent years,UV-curable polymer-based microfluidic devices have been reported as an alternative to poly(methyl methacrylate) (PMMA) or poly(dimethylsiloxane) (PDMS) and they were expected to be used for commercial prototype devices,because of their good mechanical properties,optical properties and very short curing time.It was also reported that the glass transition temperatures of these UV-curable polymers were low.By using a UV-curable polymer with low glass transition temperature (around 40oC) and structural mechanics theory,we developed a self-actuated sealing valve for a microreactor as shown in Figure 1.This sealing device is suitable for PCR chips or chemical reaction chips,which require closed reaction chambers and prevention of reaction liquid evaporation during a reaction process.This device will also be helpful for designing highly integrated microfluidic devices by featuring combined uses of micro heaters such as laser heating,ITO heaters,and micropeltier elements.