A Real-Time Thermal Self-Elimination Method for Static Mode Operated Freestanding Piezoresistive...

Area of Science:

• Biosensors
• Microelectromechanical Systems (MEMS)
• Nanotechnology

Background:

• Piezoresistive microcantilever biosensors are susceptible to thermal effects, impacting detection accuracy.
• Existing methods for thermal compensation often require bulky external equipment, limiting portability.

Purpose of the Study:

• To develop a real-time thermal compensation method for piezoresistive microcantilever biosensors.
• To eliminate thermal drift and improve the signal-to-noise ratio in biomolecular detection.
• To enable the development of miniaturized and portable biosensing devices.

Main Methods:

• Utilized an on-chip fixed piezoresistor as a temperature sensor and a microcantilever with an embedded piezoresistor as the biomolecular sensor.
• Employed the calibrated relationship between piezoresistor resistance and temperature to compensate for thermal effects.
• Implemented a real-time thermal self-elimination approach without external temperature control.

Main Results:

• Reduced the thermal effect signal from 25.6 μV/°C to 0.3 μV/°C, an improvement of approximately two orders of magnitude.
• Successfully demonstrated real-time thermal self-elimination during biomolecular detection.
• Validated the method's effectiveness in eliminating temperature coefficient of resistance (TCR) and bimorph effects.

Conclusions:

• The developed method effectively compensates for thermal effects in piezoresistive microcantilever biosensors in real-time.
• This approach facilitates the miniaturization of biosensing systems for portable applications.
• The technology holds promise for developing advanced medical devices and microarray analysis platforms.