题目：Recent Advances in Atomic Force Microscopy 

报告人：Dr.Roger Proksch, President of Asylum Research Oxford Instruments, USA 

时间：2016年1月15日（星期五），上午09:30 

地点：南楼4层会议室 

邀请人： 程志海 研究员（Tel：82545589）

摘要： 

     Since its invention in 1986, the atomic force microscope has seen a steady march of technological advancements. The Cypher AFM has a variety of advanced features that revolutionize AFM operation and measurements. In this presentation, we will demonstrate a variety of new automated features that make the AFM easy to use while simultaneously improving the accuracy, sensitivity, and speed of the measurements, while also expanding the range of applications.  

     One of the innovative automated features of the Cypher AFM system is motorized optical spot location that allows unprecedented ease of use. Automated calibration of the cantilever spring constant and sensitivity allows simple and fast quantification of the motion of the cantilever and the force between the tip and sample. This calibration in turn allows automatic optimization of the imaging parameters. These developments allow a user to load a sample and cantilever to then automatically image samples without further intervention. We will also explore the use of small cantilevers that lowers the noise floor of the instrument and increases measurement speeds while making high resolution – at the point of single atomic defect resolution or the DNA helix – routine.  

    Another early challenge in AFM has been high frequency actuation of the cantilever.  Conventional piezo actuation, while very common has some non-ideal characteristics that make measurements based on this actuation difficult to quantify. By introducing blueDrive™ photothermal actuation, we are able to significantly improve the stability, sensitivity and accuracy of a large number of imaging techniques.  We will discuss a range of applications that demonstrate the capabilities of this new feature – including contact  resonance and AM-FM viscoelastic modulus mapping – both in ambient and liquid conditions.  

    Finally, we will discuss some of the new opportunities that are enabled by the advanced environmental control options on the Cypher S and ES systems including temperature sensitive polymer phase transitions in a polypropylene-polystyrene film, concentration dependent dissolution and growth in a CaCl₂ crystal in fluid and vapor concentration induced sublimation.  

报告人简介： 

    Dr. Roger Proksch is President and co-founder of Asylum Research an Oxford Instruments company. He received his PhD in Physics from the University of Minnesota. With over 25 years of AFM experience, Dr. Proksch is an inventor/co-inventor on over 30 patents in the field of AFM, has been an invited speaker at numerous society conferences, and has been published in numerous scientific journals. He is one of the key researchers that commercialized piezoresponse force microscopy with Dr. Sergei Kalinin.