Integration of PDA Sensor onto Microfluidic Chip and Development of Cell Chip for Tissue Generation

Abstract

We develop two kinds of microchips using PDMS: a cell chip and a microfluidic chip. Interactions between cells and cell-culture materials will be studied using the cell chip. The microfluidic chip is developed for detections of target bio-molecules using in-situ fabricated polymer membrane embedding a polydiacetylene fluorescent sensor [1]. For the cell chip, a PDMS mold is prepared on a Si-wafer by standard soft lithography. Next, PDMS is spin-coated and dried on the mold to make the height of wells within 200μm. As a result, a thin-film type of PDMS well-arrays is obtained following peeling the dried PDMS off the mold. The film is located on a glass slide for optical access during cell-culture after the glass slide is treated to have aminosilated layer to immobilize nutritional proteins and cells [2]. A cell chip has ~100 wells with the diameter of 150μm, and height is ~200μm. The microfluidic chip consists of a glass substrate and a PDMS cover. A polymer membrane with the fluorescent sensors is integrated in the microchannel using in-situ laser-polymerization and phase separation technique [3]. The sensors are trapped in the pores of polymer membrane during the polymerization. Both glass substrate and PDMS cover are chemically treated for the polymer membrane to covalently bond to them. When the sensors are exposed to external stresses, like target molecules in a microchannel flow, hydrodynamic pressure increase or temperature, the sensor changes its color.