Integrated microcantilevers for high-resolution sensing and probing

Abstract

This topical review is focused on microcantilever-based sensing and probing functions that are realized by integrating a mechanically compliant cantilever with self-sensing and self-actuating elements, specific sensing materials as well as functionalized nano-tips. Such integrated cantilever devices have shown great promise in ultra-sensitive applications such as on-the-spot portable bio/chemical detection and in situ micro/nanoscale surface analysis and manipulation. The technical details of this review will be given in a sequence of cantilever sensors and, then, cantilever-tip probes. For the integrated cantilever sensors, the frequency-output style dynamic cantilevers are described first, with the contents including optimized resonance modes, sensing-group-modified nanostructures for specific bio/chemical mass adsorption and nanoscale sensing effects, etc. Thereafter, the static cantilever sensors for surface-stress detection are described in the sequence of the sensing mechanism, surface modification of the sensitive molecule layer and the model of specific reaction-induced surface-energy variation. After technical description of the cantilever sensors, the emphasis of the review moves to functionalized nano-tip equipped cantilever-tip probing devices. The probing functions are not only integrated on the cantilever but also integrated at the sharp apex of the tip. After description of single integrated cantilever probes and their applications in surface scanning and imaging, arrayed cantilever-tip devices and their simultaneous parallel operation for high throughput imaging and nanomechanical data storage are also addressed. With cantilever-tip probes as key elements, micro-analysis instruments are introduced that can be widely used for macro/nanoscale characterizations.

Effect of hydrodynamic force on microcantilever vibrations: Applications to liquid-phase chemical sensing

“…In recent years, interest in microcantilever-based chemical and biochemical sensing systems has risen due to their projected high sensitivity [1][2][3][4][5]. The large ratio of surface area to volume makes the microcantilever extremely sensitive to surface processes.…”

Hyper-branch sensing polymer batch self-assembled on resonant micro-cantilevers with a coupling-reaction route

“…The resonant micro-cantilevers are fabricated by using a standard silicon micromachining technology as we previously described in literatures [17][18][19].…”

“…Among various types of gas sensors, resonant micro-cantilevers are advantageous in ultra-high sensitivity, miniaturized size and facile integration with signalacquisition circuit [10][11][12][13][14][15][16][17][18][19]. For chemical sensing functionalization, sensing material with high specific surface area should be integrated onto the micro-gravimetric transducer of the resonant micro-cantilever.…”

Geometry optimization of uncoated silicon microcantilever-based gas density sensors

“…In recent years microcantilever-based chemical, biological and physical sensors have attracted the interest of numerous researchers due to their high surface-to-volume ratio and their high performance in both gas and liquid phases [1][2][3][4][5][6]. For chemical and biochemical sensing applications, the microcantilevers are usually coated with a sensitive layer whose purpose is to selectively sorb the analyte of interest, resulting in either a static deflection (bilayer effect) in the static mode or a shift in the resonant frequency (mass effect) in the dynamic flexural mode.…”