Christian Paulus

A 128 128 CMOS Biosensor Array for Extracellular Recording of Neural Activity

Sensor arrays are a key tool in the field of neuroscience for noninvasive recording of the activity of biological networks, such as dissociated neurons or neural tissue. A high-density sensor array complementary metal–oxide–semiconductor chip is presented with 16 K pixels, a frame rate of 2 kiloframes per second, and a pitch of 7.8 m 7.8 m for imaging of neural activity. The related circuit and system issues as well as process aspects are discussed. A mismatch-canceling calibration circuitry with current mode signal representation is used. Results from first biological experiments are presented, which prove full functionality of the chip.

A 128 /spl times/ 128 CMOS bio-sensor array for extracellular recording of neural activity

A CMOS sensor array for monitoring neural signals of living cells with 128 /spl times/ 128 pixels in a 1 mm/sup 2/ area is described. A standard 0.5 /spl mu/m, 5 V CMOS process extended by top electrodes covered by a relatively thin bio-compatible dielectric is used. Detection circuitry is based on a sensor-MOSFET mismatch-compensating current-mode technique.

A fully electronic DNA sensor with 128 positions and in-pixel A/D conversion

A 16 /spl times/ 8 sensor array chip for fully electronic DNA detection is presented. The sensor principle is based on an electrochemical redox cycling process. The chip is fabricated on the basis of an extended 0.5 /spl mu/m CMOS process. Each sensor site of the array chip contains a complete A/D converter with a dynamic range of five decades. The 3/spl sigma/-homogeneity of the electrical response of the sensor array is better than 6% (10/sup -11/ A to 10/sup -7/ A) and better than 20% (10/sup -12/ A to 10/sup -7/ A). Proper operation of the chip is demonstrated with electrochemical and biological experiments.

CMOS DNA Sensor Array With Integrated A/D Conversion Based on Label-Free Capacitance Measurement

This paper presents a fully electronic label-free DNA chip in 0.5-mum CMOS technology, with 5-V supply voltage, suitable for low-cost highly integrated applications. The chip features an array of 128 sensor sites with gold electrodes and integrated measurement, conditioning, multiplexing and analog-to-digital conversion circuitry. The circuits measure capacitance variations due to DNA hybridization on the gold electrodes which are bio-modified by covalently attaching probes of known sequence. Specificity, repeatability and parallel detection capability of the fabricated chip are successfully demonstrated

A Fully Electronic Label-Free DNA Sensor Chip

This paper presents a microfabricated DNA chip for fully electronic, label-free DNA recognition based on capacitance measurements. The chip has been fabricated in 0.5-mum CMOS technology and it features an array of individually addressable sensing sites consisting of pairs of gold electrodes and addressing logic. Read-out circuitry is built externally using standard components to provide increased experimental flexibility. The chip has been electrically characterized and tested with various solutions containing DNA samples. Significant capacitance variations due to DNA hybridization have been measured, thus showing that the approach represents a viable solution for a single chip DNA sensor array

Sensor arrays for fully-electronic DNA detection on CMOS

A 16×8 DNA sensor array chip with fully electronic readout is based on an extended CMOS process. Requirements concerning the integration of bio-compatible interface-, sensor- and transducer-materials into a standard-CMOS-environment and circuitry design issues are discussed.

A low-power true random number generator using random telegraph noise of single oxide-traps

A true random number generator is realized by utilizing the noise produced by single oxide traps in small-area MOSFETs in combination with built-in redundancy. The circuit has an area of 0.009mm2 in 0.12mum CMOS and consumes 50muW at 200kb/s random output data. The concept is robust against environmental noise and supply-voltage variations and is thus suitable for operation within security controllers

Design of an integrated potentiostat circuit for CMOS bio sensor chips

A design strategy is presented for potentiostat circuits suitable for electronic bio sensors on CMOS. Guidelines are given to guarantee stable operation under the condition of widely varying and only roughly known electrochemical parameters. A concrete design example used in a fully electronic DNA sensor array CMOS chip is shown. Measurement results with a biological analyte applied to that chip prove proper operation of the potentiostat.

A 4GS/s 6b flash ADC in 0.13 /spl mu/m CMOS

A 4GS/s 6b flash ADC with 8b output is presented realized in a 0.13 /spl mu/m standard CMOS technology. The outputs of 255 small-area comparators with comparatively large input offsets are averaged by a fault tolerant thermometer-to-binary converter. The ADC uses an on-chip low jitter VCO for clock provision and consumes 990mW at a single supply voltage of 1.5V.

A 24x16 CMOS-Based Chronocoulometric DNA Microarray

An array of 24 times 16 electrochemical sensors for detecting bio-molecules uses gold sensor electrodes added to a 0.5 mum CMOS process. Detection is based on time-resolved measurement of charge (chronocoulometry). A differential measurement technique uses a replica electrode and fast integration to suppress background offset signals