Cmos Sensor
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This document discusses the design of an active CMOS sensor array for electrochemical biomolecular detection. The sensor array allows for highly parallel analysis by miniaturizing the sensing platform and enabling multiple working electrodes on a single chip. Each sensor contains a gold working electrode that can detect changes from DNA hybridization through electrochemical techniques like cyclic voltammetry and potentiostat control circuits. While CMOS sensors provide advantages of reduced size and complexity, limitations include lack of suitable electrode materials and voltage compatibility with standard CMOS ICs.
Cmos Sensor
- 1. Active cmos sensorarray for Electrochemical Biomolecular Detection\\\\12
- 2. * Introduction* electrochemical sensing* active cmos sensor design* LIMITATION OF CMOS* conclusionA sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument.Cmos array miniaturizes the sensing platform, enhance portability,enabling high throughput ,highly parallel analysis.
- 3. Electro chemical sensing approaches to DNA detection , rely on detecting changes occurring with hybridization at interface.CMOS sensor include :A sensor chip interfaced to a single on-chip WE.
- 5. Electrochemical sensing1. Potentiostat operation2. Cyclic VoltammetryFeedback control system.Apply desired potential to elctrochemical cell.Measure the movement of charge.Low speed , large signal tech.Detect redox species.Determine probe concentration , measure DNA probe target hybridization.
- 6. Description of potentiostat operation. (a) Conceptual diagram. (b) Implementation using electronic components.
- 7. Active cmos sensor array design : Each array consist of square gold (WE)having side length 100 µm. Variation allows effect of electrode area on the cell current for different redox and biomolecular reaction. Dual slope ADC.
- 8. Active COS sensor array architecture.
- 9. 1. Electrochemical cell model Small signal model simulate system behavior and test potentiostat stability when chip is operated in electrolyte. 2. Potentiostat circuits To provide good noise performance stability across wide range of operating condition.3. Chip post processing & Experimental setup Used to create an array of Au elect. on the surface. packaged chip in PCB socket with top plate layer.
- 10. . Small-signal circuit models of (a) the electrode–electrolyte interfaces present in an electrochemical cell and (b) the WE–electrolyte interface augmented with noise sources.
- 12. Limitation of electrochemical cmossensors : Lack of proper electrode. Voltage limitation of cmosic. Require 100-1000 V for proper operation.
- 13. conclusion :1. Eliminate the need for bulky and expensive optical equipment used in florescent based microarray.2. Reduction in size & complexity.
- 14. THANKS