Cells adhered and cultured on microcantilevers

This paper shows a novel method to cultivate cells on a π-shape microcantilever inside a polydimethylsiloxane microfluidic system. Only one lithography step was needed to precisely align and pattern a poly(2-hydroxyethyl methacrylate) hydrogel microstructure, of size 200 × 200 μm, onto a silicon nitride microcantilever inside the PDMS microfluidic device. Gelatin was used as a sacrificial layer to resolve the issue of the microfluidic and hydrogel microstructure sticking together, successfully releasing the microcantilevers. BHK-21 cells were successfully laden and cultivated on the hydrogel microstructures of microcantilevers for 24 h. The optical system consisted of a He–Ne laser, a charge-coupled device camera, and a position-sensitive detector, which was used to measure the deflections of the microcantilevers due to the laden cells. The deflection increased continually during the cell-laden period. Meanwhile, the deflection increased with increasing cell concentration. By repeating the cell-laden and culture experiment three times, the magnitude and trend of deflection of microcantilevers were almost the same. It demonstrates that the microcantilever-based biochip has adequate stability and provides reliable measurement results for drug screening applications in the future.