Nanomechanical Membrane-type Surface Stress Sensor
Nanomechanical Membrane-type Surface Stress Sensor
复制标题
DOI：
10.1021/nl103901a
复制
发表时间：
2011-03-01
期刊：
影响因子：
10.8
通讯作者：
Rohrer, Heinrich
中科院分区：
文献类型：
--
作者：
Yoshikawa, Genki;Akiyama, Terunobu;Rohrer, Heinrich
纳米机械悬臂梁传感器已成为一个关键的设备，用于实时和无标记检测各种分析物，从气体到生物分子。主要的传感原理是基于分析物引起的表面应力，这使得悬臂梁弯曲。在这封信中，我们提出了一种薄膜型表面应力传感器（MSS），这是基于压阻读出集成在传感器芯片。MSS不是一个简单的“悬臂梁”，而是由四个压阻“传感梁”悬挂的“吸附物膜”组成，构成一个完整的惠斯通电桥。整个分析引起的各向同性的表面应力的膜有效地转换到压阻梁作为放大的单轴应力。在本实验中使用的原型MSS的评价表明，这是一个高的灵敏度，这是与光学方法相比，一个因素超过20高出与标准的压阻悬臂获得。有限元分析表明，改变膜和梁的尺寸可以大大提高灵敏度进一步。鉴于集成压阻读出的各种便利和优势，该平台有望开启基于表面应力的传感新时代。
Nanomechanical cantilever sensors have been emerging as a key device for real-time and label-free detection of various analytes ranging from gaseous to biological molecules. The major sensing principle is based on the analyte-induced surface stress, which makes a cantilever bend. In this letter, we present a membrane-type surface stress sensor (MSS), which is based on the piezoresistive read-out integrated in the sensor chip. The MSS is not a simple "cantilever," rather it consists of an "adsorbate membrane" suspended by four piezoresistive "sensing beams," composing a full Wheatstone bridge. The whole analyte-induced isotropic surface stress on the membrane is efficiently transduced to the piezoresistive beams as an amplified uniaxial stress. Evaluation of a prototype MSS used in the present experiments demonstrates a high sensitivity which is comparable with that of optical methods and a factor of more than 20 higher than that obtained with a standard piezoresistive cantilever. The finite element analyses indicate that changing dimensions of the membrane and beams can substantially increase the sensitivity further. Given the various conveniences and advantages of the integrated piezoresistive read-out, this platform is expected to open a new era of surface stress-based sensing.