Development of direct point-force detection type piezoresistive cantilever array biosensor

微悬臂梁阵列传感器是一种具有广阔应用前景的传感器平台。压阻式悬臂梁可以克服传统光学(激光)读出方法中的实际问题，但由于其灵敏度极低，在传感应用中尚未得到广泛应用。在本研究中，我进行了全面的优化，打破了悬臂梁的常规做法，最终研制出了膜式表面应力传感器(MSS)。我在实验中证明，即使用第一个原型芯片，灵敏度也比传统的压阻式悬臂梁高20多倍，已经达到了与光学读出悬臂梁类似的灵敏度。此外，有限元分析表明，只要改变吸附膜和传感梁的尺寸，它的灵敏度就有可能进一步提高几个数量级。

Micro cantilever array sensors have been emerging as a promising platform for various applications. Piezoresistive cantilevers, which can overcome practical problems in the conventional optical (laser) read-out method, had not been widely in use for sensing applications because of their critically low sensitivity. In this study, I made a comprehensive optimization, breaking the bounds of common practice of "cantilever", and finally developed a Membrane-type Surface stress Sensor (MSS). I experimentally demonstrated more than 20 times higher sensitivity than that of conventional piezoresistive cantilevers even with the first prototype chip, already reaching the similar sensitivity with that of optically read-out cantilevers. Furthermore, the finite element analyses indicate its high potential for further enhancement in sensitivity up to several orders of magnitude just by changing the dimensions of the adsorbate membrane and sensing beams.