Microfluidic-integrated laser-controlled microactuators with on-chip microscopy imaging functionality†
The fabrication of a novel microfluidic system, integrated with a set of laser-controlled microactuators on an ePetri on-chip microscopy platform, is presented in this paper. In the fully integrated microfluidic system, a set of novel thermally actuated paraffin-based microactuators, precisely controlled by programmed laser optics, was developed to regulate flow and to provide pumping of liquid solutions without external connections. The microfluidic chip was fabricated on a complementary metal–oxide–semiconductor (CMOS)-imaging sensor chip on an ePetri platform; this configuration provided real-time, wide field-of-view, high-resolution imaging using a sub-pixel sweeping microscopy technique. The system of microactuators, which consisted of microvalves and a micropump, operated well in the microfluidic channel with a focused near-infrared laser beam providing the actuation control. As a demonstration, we used our prototype to assess cell–drug interactions and to monitor cell growth directly within an incubator in real time. The powerful combination of laser-actuated microfluidics and chip-scale microscopy techniques represents a significant step forward in terms of a simple, robust, high-throughput, and highly compact analysis system for biomedical and bioscience applications.