Microscale Photodetectors for Biophotonics


Optical techniques such as fluorescence, bioluminescence, absorption, and scattering are wide-adopted in science and medicine. Most of today’s optical instruments employ photodetectors solely for light detection, deferring optical functions (e.g., spectral separation) and associated sensor complexities onto the system level, i.e., off the semiconductor chip. This contributes to bulky and inflexible instrumentations. To mitigate this technological gap, a photo gate with voltage-programmed spectral absorption property for multi-color fluorescence had been recently developed by the PI and his colleagues. This device uses only a standard CMOS fabrication process with no filter or grating. Since the device has no external optical components and no moving parts, it is well suited for use within a microsystem.


The goal of this project is to innovate in biophotonic detector devices to enable substantial size reduction in optical instruments. Our approach is to build various complex optical functionalities right into the microscale photodetector through novel integration of micromechanical structures and sensing materials.


Microscale biophotonic photodetectors will enable point-of-care medical diagnostic devices that can dramatically improve accessibility to healthcare for the patient, by making the devices more portable, cheaper, and easier to operate by the non-trained person.


Areas of study: photodetector design, microfabrication, biophotonic techniques

Supervisor: Dr. Derek HO (derekho@cityu.edu.hk; www.atomstosystems.com)

Suitable for: M.Phil./Ph.D.