Ultra-sensitive NEMS-based cantilevers for sensing, scanned probe and very high-frequency applications
Ultra-sensitive NEMS-based cantilevers for sensing, scanned probe and very high-frequency applications
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DOI：
10.1038/nnano.2006.208
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发表时间：
2007-02-01
影响因子：
38.3
通讯作者：
Roukes, M. L.
中科院分区：
文献类型：
--
作者：
Li, Mo;Tang, H. X.;Roukes, M. L.
扫描探针显微镜（SPM）和基于MEMS的传感器通常使用微尺度尺寸或更大尺寸的低频机械装置。几乎普遍地，片外方法用于感测这些器件中的位移，但这种方法不适合纳米级器件。纳米级机械传感器提供了一个大大增强的性能，这是无法达到的微米级设备。在这里，我们描述了自感知纳米antilevers的制造和操作的基本机械共振到非常高的频率（VHF）。这些器件使用基于压阻式薄金属膜的集成电子位移传感器，允许直接和最佳的纳米器件读出。这种非光学传感器能够满足以前无法达到的灵敏度和带宽要求，例如快速SPM和VHF力传感。127 MHz的悬臂梁振动的检测证明与热机械噪声限制位移灵敏度为39 fm Hz（-1/2）。我们最小的器件尺寸接近大气压下的平均自由程，在环境条件下保持高谐振品质因数。这使得能够在室温下在空气中进行化学吸附测量，具有前所未有的小于1阿托克（10（-18）g）的质量分辨率。
Scanning probe microscopies (SPM) and cantilever-based sensors generally use low-frequency mechanical devices of microscale dimensions or larger. Almost universally, off-chip methods are used to sense displacement in these devices, but this approach is not suitable for nanoscale devices. Nanoscale mechanical sensors offer a greatly enhanced performance that is unattainable with microscale devices. Here we describe the fabrication and operation of self-sensing nanocantilevers with fundamental mechanical resonances up to very high frequencies ( VHF). These devices use integrated electronic displacement transducers based on piezoresistive thin metal films, permitting straightforward and optimal nanodevice readout. This non-optical transduction enables applications requiring previously inaccessible sensitivity and bandwidth, such as fast SPM and VHF force sensing. Detection of 127 MHz cantilever vibrations is demonstrated with a thermomechanical-noise- limited displacement sensitivity of 39 fm Hz(-1/2). Our smallest devices, with dimensions approaching the mean free path at atmospheric pressure, maintain high resonance quality factors in ambient conditions. This enables chemisorption measurements in air at room temperature, with unprecedented mass resolution less than 1 attogram (10(-18) g).