Two Dimensional Array of Piezoresistive Nanomechanical Membrane-Type Surface Stress Sensor (MSS) with Improved Sensitivity

Abstract

We present a new generation of piezoresistive nanomechanical Membrane-type Surface stress Sensor(MSS) chips, which consist of a two dimensional array of MSS on a single chip. The implementation of several optimization techniques in the design and microfabrication improved the piezoresistive sensitivity by 3∼4 times compared to the first generation MSS chip, resulting in a sensitivity about ∼100 times better than a standard cantilever-type sensor and a few times better than optical read-out methods in terms of experimental signal-to-noise ratio. Since the integrated piezoresistive read-out of the MSS can meet practical requirements, such as compactness and not requiring bulky and expensive peripheral devices, the MSS is a promising transducer for nanomechanical sensing in the rapidly growing application fields in medicine, biology, security, and the environment. Specifically, its system compactness due to the integrated piezoresistive sensing makes the MSS concept attractive for the instruments used in mobile applications. In addition, the MSS can operate in opaque liquids, such as blood, where optical read-out techniques cannot be applied.

Finite Element Analysis on Nanomechanical Sensing of Cellular Forces

“…The dimensions for the MSS were set according to the previous report. 14 The diameter and the thickness of the membrane were 500 and 2.5 μm, respectively (Fig. 5).…”

“…Considering that the limits of detection of a cantilever-type sensor and an MSS are ~1 nm (= d) and ~5 × 10 -6 (=ΔRtot/Rtot), respectively, 7,14 it is difficult to obtain clear sensing signals by using these sensors even though cells synchronize their motions (Fig. 8).…”

Design and Manufacturing of Electromechanical Chip for Rapid Measurement of IgG1 Antibody in Cell-Culture Supernatant

“…The intrinsic noise level for the modified piezoresistor can be estimated by Johnson (thermal) and Hooge (1/f ) noise equations [24][25][26]. The total intrinsic noise for NMR is reported as 0.01-0.5 µV [18,27], which is still lower than the experimental noises (2.0~2.5 µV), mainly caused by the electrical circuit.…”

Comparing membrane- and cantilever-based surface stress sensors for reproducibility

“…We recently developed a membrane-type surface stress sensor (MSS) that has already shown a remarkably improved sensitivity compared to that of conventional piezoresistive cantilevers [22,23]. In this study, we investigate the sensor-to-sensor reproducibility of MSS and compare it with that of a classic piezoresistive cantileverbased sensor.…”