Wide dynamic range pulse modulation image sensor for on-chip bioimaging applications

Image sensors with a pulse modulation measurement scheme are fabricated for bioimaging and biosensing applications. We designed pulse modulation photosensors and a 64/spl times/64-pixel image sensor. We demonstrated the feasibility of the pulse modulation measurement scheme for biosensing applications. We obtained a dynamic range of 120 dB and minimum sensing intensity level of 2 nW/cm/sup 2/. We also confirmed that 0.2% of intensity change is detectable at the minimum intensity region. An in-vitro, on-chip imaging of a mouse hippocampus was successfully demonstrated.