A grant has been awarded to Dr. David Dickensheets at Montana State University to develop a new instrument for electronic focus and aberration control in biological microscopy, with particular application to microscopy of thick living tissues or intact animals. A critical tool for studying living systems in their natural state, high-resolution microscopy of living and intact tissues remains a tremendous challenge. This project addresses a major technological barrier for in vivo microscopy: controlling the focus and managing aberrations when imaging through thick, unprepared specimens. Most current instruments for vital microscopy rely on mechanically fixing the specimen in some manner and then translating the microscope objective lens in or out to adjust focus. A system has been developed based on a deformable MEMS mirror (MEMS is an acronym for micro-electromechanical systems) that adjusts the location of the beam focus in the sample while maintaining the objective lens in a fixed position. There is no mechanical translation of any lenses or of the sample, and therefore no vibration. Precise control of the mirror shape eliminates spherical aberration at every depth. Fast response time allows focus stepping or scanning, and when synchronized with lateral beam scanning allows sectioning of 3D samples along any oblique plane or even along convoluted surfaces such as a cell membrane. No competing technology offers the precision, speed and potential low cost afforded by MEMS deformable mirror technology. The underlying technology of electronic focus and aberration control using a MEMS deformable mirror has been demonstrated in our laboratory. The aim in this project is to bridge the gap between our first prototype demonstration and an instrument ready for commercialization and broad distribution. When fully developed, this technology will turn any laser scanning confocal or two-photon/multi-photon microscope into an electronically controlled 3D imaging instrument, capable of x-y, x-z or arbitrary trajectory scanning. With the proposed instrument and future software development, many sophisticated image acquisition schemes would become possible including multi-plane imaging, enhanced depth of focus at high NA, and image feature tracking and stabilization. The scope of potential use for this new technology is extremely broad. The first module in development is for scanning laser microscopes, but future applications include fast, aberration-free electronic focus control for wide-field white light and fluorescence microscopes and miniaturized in-vivo microscopes designed for laparoscope, endoscope or catheter platforms that presently have extremely limited ability to adjust focus in situ. Advances made with the deformable mirrors will be of interest for applications in astronomy, photography and optical data storage. In addition to its scientific impact the project embraces integration of research and education, training one female engineering Ph.D. student and providing research experience for several undergraduate engineering students, who will participate directly in cross-disciplinary activities with biology researchers as they vet the technology. This project will also participate in an established summer internship program for students and faculty from tribal colleges in Montana.
