Low-noise, wide dynamic range sigma delta sensor interface with applications in microfluidic cell sorting
Abstract
The proposed low-noise wide dynamic range sigma-delta sensor interface minimizes the optical detection system size and complexity, while maximizing its overall efficiency (power and sensitivity) of a multi-stage microfluidic cell sorter system. The proposed sigma-delta based sensor interface modulates the sensed analog current signal generated from a given sensor, e.g. an APD, and generates a corresponding semi-digital pulse density modulated (PDM) signal. The resulting sensor interface has a superior noise response and achieves at least one order of magnitude higher sensitivity while consuming less power (2-mW) as compared to the traditional operational amplifier based transimpedance amplifier sensor interface. Using a digital signal processor and a digital low-pass filter, the sensed analog signal can be recovered from the PDM signal. The proposed sigma-delta sensor interface will be used to enhance the optical detection system of a multi-stage microfluidic cell sorter, aiding in the development of a fully enclosed cell sorting system that would be a great advancement in microfluidic cell sorting technology.
Degree
M.S.E.C.E.
Advisors
Jung, Purdue University.
Subject Area
Analytical chemistry|Electrical engineering
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