Neurotransmitters and their Detection

1. Neurotransmitters and their Detection • Introduction • Design • Testing • Application • Conclusion

2. Electrochemical Measurements • Introduction • Design • Testing • Application • Conclusion

3. Electrode Bulk solution Solution Osurf Obulk O’ O’ads ne− CURRENT R’ads Osurf Rbulk O’ Adsorption/Desorption Chemical reaction Electron transfer Mass transfer Overall Electrochemical Reaction • Introduction • Design • Testing • Application • Conclusion

4. VREDOX Multiplexed digital bitstream Analog to Digital Convertor (ADC) IIN 1 Register Analog to Digital Convertor (ADC) IIN 2 Register …. …. …. • Introduction • Design • Testing • Application • Conclusion Conceptual VLSI Design • Why VLSI ? • Multichannel • Low power • Integration with microfabricated sensors • Implantable • ‘Black box’ design -

5. Difference Integrator Comparator Latch ∫ Bitstream D Q IIN CLK 1 bit DAC IREF A {+1, −1} _ + D ADC:First order Delta-Sigma Modulator • Introduction • Design • Testing • Application • Conclusion • Why ΔΣ convertor ? • Low frequency of IIN • Bandwidth Resolution tradeoff • High oversampling ratio (OSR) • Noise shaping by OSR A problem: the average output level at the 1 bit DAC must be of the same order as the input signal level. Thus a fixed IREF cannot handle widerange IIN

6. Novel ΔΣ Modulator with time modulated feedback • Introduction • Design • Testing • Application • Conclusion

7. Introduction • Design • Testing • Application • Conclusion Clock Generation

8. Introduction • Design • Testing • Application • Conclusion System Block Diagram

9. Introduction • Design • Testing • Application • Conclusion VLSI Chip Micrograph