Integrated CMOS optical sensor for cell detection and analysis

To circumvent the complexity of the detection systems of microfluidic devices, Hartley et al. recently reported on a CMOS optical active pixel sensor (APS) for near-field detection and counting of microscopic particles. To further enhance the digital cytometric capabilities of the original sensor, we modified and utilized a dual APS-array scheme to facilitate the determination of the velocity and size of particles flowing in microfluidic channels. Our findings indicate that the prototype dual-APS sensor is capable of detecting particle velocities up to ∼500 μm/s and particles with diameter in the range of 5–15 μm. The dual APS CMOS sensor, as a result of the hybrid integration with a microfluidic, provides a low cost and practical means of noninvasively monitoring the contents of microfluidic and lab-on-a-chip devices.