Nanochemical surface analyzer in CMOS technology
详细信息 查看全文
- 作者：Franks ; W. ; Lange ; D. ; Lee ; S. ; Hierlemann ; A. ; Spencer ; N. ; Baltes ; H.
- 关键词：018 ; 032 ; Chemical force microscopy ; AFM ; Self-sensing AFM cantilevers ; Chemically modified AFM tips
- 刊名：Ultramicroscopy
- 出版年：2002
- 出版时间：May, 2002
- 年：2002
- 卷：91
- 期：1-4
- 页码：21-27
- 全文大小：192 K
文摘
We have developed an atomic force microscopy (AFM) cantilever system, fabricated using a standard CMOS process and a few post-processing steps, capable of detecting the difference between hydrophilic and hydrophobic samples for the purpose of nanochemical surface analysis. The fully integrated cantilever comprises a thermal actuator for cantilever deflection and a Wheatstone bridge to sense cantilever bending, thus obviating the need for cumbersome laser detection and external piezoelectric drives. Glass microspheres have been affixed to the cantilevers and, were either modified with a self-assembled monolayer to form hydrophobic tips, or left unmodified for hydrophilic tips. Force–distance curves have been used to measure the force between the functionalized/unfunctionalized tips and hydrophobic/hydrophilic sample surfaces. In an optimization step three different Wheatstone bridge sensors have been designed and characterized; best Wheatstone bridge sensitivity is 8.0μV/nm with a 713nm/mW actuator efficiency.