Resonant Enhanced Infrared Nano-Spectroscopy (REINS)

Infrared spectroscopy is the most widely used technique for chemical characterization with a worldwide market of over $1B annually. Conventional infrared spectroscopy suffers, however, from fundamental spatial resolution limits that prohibit its application at the nanoscale. This has prevented widespread use of IR spectroscopy in the growing field of nanoscale materials. The atomic force microscope (AFM) on the other hand excels at nanometer level spatial resolution, but has lacked any robust technique for chemical characterization. A new technique was recently developed that combines AFM and infrared spectroscopy (AFM-IR) to provide chemical analysis on sub-100 nm length scales. This project aims to dramatically increase the sensitivity and range of samples that can be measured with the AFM-IR technique. These improvements will enable nanoscale chemical analysis on a wide range of samples including materials for energy generation and storage (for example organic photovoltaics) and biological materials under physiological conditions. This project involves a close collaboration between Anasys Instruments and Prof. Mikhail Belkin of the University of Texas at Austin. The project is developing a novel form of AFM-IR called Resonance Enhanced Infrared Nanospectroscopy (REINS) in which an IR light source is pulsed at a frequency corresponding to a resonant frequency of an AFM cantilever probe. This resonance enhancement enables nanoscale infrared spectroscopy on samples that have previously been beyond the detection limit of the AFM, down to the level of single molecular monolayers. In Phase I the team demonstrated the ability to enhance the sensitivity of AFM-IR chemical spectroscopy by 100X over previous performance. With this improved sensitivity, the team demonstrated chemical spectroscopy on extremely thin films, down to the scale of a single molecular monolayer. Among other accomplishments, the team also demonstrated the ability to extend AFM-IR capabilities to allow measurements in liquids, enabling nanoscale chemical analysis in physiological and electrolytic environments. In Phase II the team will develop a commercial prototype REINS AFM-IR system leveraging sensitivity and resolution accomplishments in Phase I. The project integrates infrared laser sources, high sensitivity AFM probes and AFM measurement control systems to enable push button nanoscale chemical spectroscopy on a robust commercial platform. Commercial Applications and Other Benefits: This project will have wide ranging applications in many areas of materials and life sciences. The REINS instrument will provide researchers the ability to examine the chemical content of complex samples on length scales previously unavailable. This new tool will accelerate the development of novel materials for energy generation and storage and structural materials that are lighter and stronger, providing significant energy savings. The improved sensitivity developed during this project will also enable accelerated development of advanced coatings and functional nanostructures, materials where significant material and device capabilities originate from very thin chemical coatings. The REINS platform will also provide insights in biology and in biomedical areas due to the ability to perform IR spectroscopy with sub-cellular spatial resolution.