A Real-Time Thermal Self-Elimination Method for Static Mode Operated Freestanding Piezoresistive Microcantilever-Based Biosensors

Abstract

Here, we provide a method and apparatus for real-time compensation of the thermal effect of single free-standing piezoresistive microcantilever-based biosensors. The sensor chip contained an on-chip fixed piezoresistor that served as a temperature sensor, and a multilayer microcantilever with an embedded piezoresistor served as a biomolecular sensor. This method employed the calibrated relationship between the resistance and the temperature of piezoresistors to eliminate the thermal effect on the sensor, including the temperature coefficient of resistance (TCR) and bimorph effect. From experimental results, the method was verified to reduce the signal of thermal effect from 25.6 μV/°C to 0.3 μV/°C, which was approximately two orders of magnitude less than that before the processing of the thermal elimination method. Furthermore, the proposed approach and system successfully demonstrated its effective real-time thermal self-elimination on biomolecular detection without any thermostat device to control the environmental temperature. This method realizes the miniaturization of an overall measurement system of the sensor, which can be used to develop portable medical devices and microarray analysis platforms.

A Genosensor Based on the Modification of a Microcantilever: A Review

“…The detection limit reached the order of a nanogram. Figure 6 C shows how, in 2018, Ku et al [ 78 ] integrated a temperature compensation resistor on the piezoresistive microcantilever, which can reduce the influence of the resistance thermal effect and dual piezoelectric wafer effect from 25.6 μV/°C to 0.3 μV/°C.…”

“… Improved scheme of electric signal extraction method. ( A ) Schematic of the interaction between probe and target molecules on an embedded-MOSFET cantilever system [ 76 ]; ( B ) schematic diagram of infrared pyroelectric detection system based on a PZT microcantilever [ 77 ]; ( C ) piezoresistive microcantilever sensor chip design with temperature compensation resistance [ 78 ]. …”

Portable Real-Time Detection of Pb(II) Using a CMOS MEMS-Based Nanomechanical Sensing Array Modified with PEDOT:PSS

“…We adopted the commercial standard CMOS process and the MEMS post-process (TSMC 0.35 µm 2P4M CMOS MEMS process) to fabricate sensing chips. Meanwhile, we designed the on-chip thermal effect self-elimination configuration [ 29 ] integrated into the CMOS process for rendering the whole sensing system portable. In addition, we modified the poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) on the sensing microcantilever by using a direct ink extrusion printing.…”

A Low Spring Constant Piezoresistive Microcantilever for Biological Reagent Detection

“…In 2017, Patkar et al created a dynamic mode piezoresistive microcantilever with a spring constant of 0.2 N/m, a deflection sensitivity of 0.3 ppm nm −1 , and a resonant frequency at 22.5 kHz [ 10 ]. In 2018, Ku et al invented a piezoresistive microcantilever using SiO 2 , Si 3 N 4 , and polysilicon, which realized a minimum detection limit of C-reactive protein (CPR) concentration at 100 μg with 3.1 N/m surface stress change by a temperature compensation [ 11 ]. Xu et al introduced a piezoresistive microcantilever with silicon nanopillars and ZnO nanorod on the top of the surface, which achieved an increase of the surface area by a factor of about 100 and a 2.1 ppb detection limit of NO 2 detection [ 12 , 13 ].…”