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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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Several recently developed techniques based on a combination of infrared (IR) spectroscopy and atomic force microscopy (AFM) have demonstrated the ability to perform chemical mapping far below the diffraction limit of light. These include scanning scattering near-field optical microscopy (sSNOM) [1], photothermal induced resonance (PTIR) [2], and the subject of this paper, Photo-induced Force Microscopy (PiFM) [3, 4]. These techniques are complementary and are based on physically distinct sensing mechanisms. While sSNOM relies on collection of scattered light, PTIR and PiFM exploit mechanical detection of IR absorption in the sample. PTIR detects cantilever vibrations arising from rapid thermal expansion of the sample in response to absorption of pulsed IR light. Although PiFM also detects cantilever vibrations in response to pulsed IR, the experimental setup and behavior of the system show clear differences between PiFM and PTIR, which indicates that the thermal expansion is not the dominant mechanism behind PiFM.
Dr. Park received a BS in Physics from Pomona College, a Ph.D. in Applied Physics from Stanford, and was a post-doc at IBM’s Watson Research Center. He has a long and distinguished 25-year history in R&D, engineering, marketing, and sales developing scanning probe microscopy techniques, most notably as the co-founder of Park Scientific Instruments one of the earliest commercially-available AFM systems.
[1] N. Ocelic, A. Huber, and R. Hillenbrand, Appl. Phys. Lett. 89 (2006), p. 101124.
[2] A. Dazzi, R. Prazeres, F. Glotin, and J.M. Ortega, Infrared Phys. Technol. 49 (2006), p. 113.
[3] I. Rajapasksa, K. Uenal, and H.K. Wickramasinghe, Appl. Phys. Lett. 97 (2010), p. 073121.
[4] D. Nowak et al., Sci. Adv. 2 (2016), p. e1501571.
Pizza lunch will be served
