Microreactor array platform featuring MEMS/microfluidic components for addressable multiplex synthesis and assays

There has been a rapidly growing interest in the large-scale integration of chemical and biomedical processes on microchips which is analogous to the concepts of VLSI microelectronic circuits. We are specifically developing microarray platforms that can provide parallel processing of many distinct reactions/assays, and therefore allow multiplex experiments such as large-scale screening and discovery to be conducted with unprecedented speed and at substantially reduced costs. Microfluidic components are integrated into the microarray platform to achieve reliable on-chip flow manipulation. We first developed a compact microvalve array with improved chemical resistance. The device was fabricated using combined silicon and polymer micromachining. A robust multiplexing algorithm was also proposed to minimize the number of signal inputs required to address a large array. Then we successfully fabricated a microreactor platform featuring active array addressing by the chemical-resistant microvalve array. This versatile microarray demonstrates superior chemical compatibility and ability to handle large dynamic range of flow rates; and therefore supports a wide spectrum of reactions/processes. Next, a novel light-writable microactuator array is presented. This work features the innovative use of a digital projector to provide patterned heating on the microchip through focused light patterns. This unique approach can achieve simultaneous thermal actuation of arbitrary units in a microactuator array with exceptional ease and flexibility. We also implemented a unique latched operation using phase change of paraffin wax, which allows the device to self-maintain the actuation status without the need for external energy or force. Finally we integrated the microactuator array and bell-shape microfluidic channels to develop a normally closed and light-configurable microfluidic network. This network maintains its configuration without using any power, behaving like a microfluidic "flash memory". We believe the proposed approach provides a unique array solution with unparalleled convenience and flexibility for lab-on-a-chip systems.