Neurotransmitters and their Detection Introduction Design Testing Application Conclusion

Electrochemical Measurements Introduction Design Testing Application Conclusion

Electrode Solution Bulk solution Adsorption/DesorptionChemical reaction Electron transferMass transfer ne − O ’ ads R ’ ads O’O’ O surf O bulk R bulk O’O’ O surf CURRENT Overall Electrochemical Reaction Introduction Design Testing Application Conclusion

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

ADC:First order Delta-Sigma Modulator Introduction Design Testing Application Conclusion Why ΔΣ convertor ? Low frequency of I IN Bandwidth Resolution tradeoff High oversampling ratio (OSR) Noise shaping by OSR + _ ∫ D A D Q CLK I IN I REF DifferenceIntegratorComparator Latch 1 bit DAC Bitstream {+1, −1} 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 I REF cannot handle widerange I IN

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

Clock Generation Introduction Design Testing Application Conclusion

System Block Diagram Introduction Design Testing Application Conclusion

VLSI Chip Micrograph Introduction Design Testing Application Conclusion