A Double-Side CMOS-CNT Biosensor Array With Padless Structure for Simple Bare-Die Measurements in a Medical...

Area of Science:

• Sensor Technology
• Materials Science
• Electrical Engineering

Background:

• Standard CMOS processes are limited in bare-die measurement capabilities for medical environments.
• Existing sensor arrays often require complex packaging and multiple connections.
• Carbon nanotube (CNT) integration offers potential for enhanced sensor performance.

Purpose of the Study:

• To develop a double-side CMOS-carbon nanotube (CNT) sensor array for simple bare-die measurements in medical settings.
• To enable robust measurements using integrated back-side rectifying diodes and high latch-up resistance.
• To simplify power and I/O connections using a single line for both functions.

Main Methods:

• Utilized a 0.35 μm standard CMOS process for sensor array fabrication.
• Implemented a double-side contact scheme with front-side ring and back-side plate structures for power and I/O.
• Developed a modified universal asynchronous receiver/transmitter (UART) serial communication with pulse-based I/O signaling.
• Incorporated level-sensitive switch control and a double sampling difference amplifier to minimize errors and power dissipation.

Main Results:

• Achieved robust measurements with inherent back-side rectifying diodes and high latch-up resistance.
• Enabled power and single I/O line communication through a unique conditioning of the I/O line.
• Demonstrated stable operation with maximum power consumption under 150 mW at a 2 MHz data rate.
• Designed and implemented a controller chip with a special I/O protocol for single-line command and data transfer.

Conclusions:

• The developed double-side CMOS-CNT sensor array offers a simplified and robust solution for bare-die medical measurements.
• The innovative single-line communication and power delivery scheme reduces complexity and enhances reliability.
• This technology paves the way for more integrated and efficient bio-sensing applications.