CMOS-Embedded Microfluidics for Channel-Addressable Parallel Readout of Spad Fluorescence Lifetime Sensors

We present the integration of CMOS-embedded subtractive microfluidics with single-photon avalanche diode (SPAD) fluorescence lifetime sensors, enabling independent channel addressability for parallel readout. Microfluidic channels are realized by selectively wet-etching the back-end-of-line (BEOL) metal routing above the SPAD sensors, reducing the analyte-to-active-region spacing to 7 μm while allowing for precision alignment. Simultaneous readout from two SPADs underneath two separate fluidic channels is demonstrated, establishing a pathway toward a scalable, multiplexed lab-on-CMOS biosensing platform.