Seth Kenkel is a Ph.D. candidate in mechanical engineering and advised by bioengineering professor Rohit Bhargava.
Research summary:
While several near-field imaging techniques now provide nanoscale chemical maps by combining molecular vibrational spectroscopies with Atomic Force Microscopy (AFM), data are often complicated by the measurement apparatus, light matter interaction scheme and the low signal to noise ratio. In this thesis, we study the contrast mechanism of contact mode Atomic Force Microscopy – Infrared (AFM-IR) spectroscopic imaging to enable accurate, nanoscale infrared absorption imaging. We first describe the image formation analytically and use this understanding to develop a new approach for correcting probe-sample coupling artifacts to enable accurate chemical imaging. We improve the design with new controls to improve the Signal to Noise Ratio (SNR) by >5x enabling minimal noise AFM-IR. Finally, we investigate the thermoelastic sample response to assess the imaging performance such as resolution and use this understanding to develop algorithms to map absorption in 3 dimensions.
