Portable Electron Microscopy and Microanalysis in Extreme Environments

Abstract

Electron microscopy (EM) is a highly attractive tool for many applications due to its unique blend of strong optical scattering, high native resolution, large depth of focus, and variety of signals including characteristic Xray emission, enabling high-magnification structural imaging and chemical analysis. Despite high optical performance and versatility supporting a wide variety of industries from basic science research to industrial process monitoring, EM has through its ~100-year history been widely regarded as a high-end tool with limited reach outside the laboratory, in particular due to inherent complexity and need for vacuum. Making EM accessible outside constrained laboratory environments will bring EM's performance and versatility to a much broader range of scientific and engineering endeavors.EM's are traditionally housed in centers at universities and large research institutions where those without access to on-site EM typically send samples to be imaged, at great expense and often with delay of weeks to months for complex analyses. For current field work, samples must be sent back to a facility where they can experience chemical or morphological changes over time and/or may be damaged in transit and cannot be reliably analyzed. On-site EM -defined here as EM for immediate portable use in remote or extreme environments at or near the site of sample collection -has historically been impractical.Mochii™ is a portable commercial scanning EM developed by the coauthors at Voxa in Seattle, WA to address the need for EM outside the laboratory (Fig. 1) [1]. This tiny low voltage microscope, which fits in the overhead bin of an airplane, has features that bring accessible and on-demand EM imaging to new applications previously hindered by size, complexity, and cost. Among these features are hand-carryable form-factor and low power consumption (0.25m tall, <12 kg, <80 W), user-friendly native wireless tablet interface, multi-user and remote capabilities, an integrated metal evaporator for easy sample preparation, and optional energy-dispersive X-ray analyzer for chemical identification [2]. The cost to own and operate a Mochii microscope is a fraction of the cost of typical EM's possessing similar imaging performance due to its low power consumption, simple design, and commoditized user-replaceable consumables. At the meeting we will report on use of EM and considerations for use in extreme field environments, such as outdoors under battery power, on moving vehicles such as ocean vessels, and perhaps the most extreme of environments: space (low earth orbit (LEO) and deep space).We are in process to prepare Mochii for manned spaceflight. Ground-based versions of EM's have been essential in NASA research for many years. In mineralogy and petrology, for example, EM is used to understand the origin and evolution of the solar system, particularly rocky bodies, through detailed study of asteroidal and cometary samples. In microbiology, EM has been used to visualize the architecture of tissues and cells to understand ...

Astrovirology: how viruses enhance our understanding of life in the Universe

“…Microscopy technologies paired with spectroscopic techniques, can inform the physical shapes and boundaries belonging to certain chemical or mineralogic compositions (Zhang et al, 2013). While an atomic force microscope was used during the Phoenix Mars Lander to investigate Martian soils (Pike et al, 2011) and recently, a scanning electron microscope was added to the ISS (Own et al, 2018) higher performance complex space-qualified microscopes have yet to be developed that can reliably detect virus-like particles. Another technique that could be applied to space virology is NanoSIMS, which performs in situ quantitative trace sample analysis with exceptional sensitivity and spatial resolution (Mayali, 2020;Pett-Ridge and Weber, 2022).…”

“…Much work remains to integrate both engineering and science perspectives. While some instrumentation, such as light, electron and atomic force microscopy, has been used on Mars and in space on the ISS (Pike et al, 2011;Own et al, 2018), instrumentation in development must also be tested in extreme analogue environments to explore and overcome limitations. Moreover, for planetary protection purposes, utilizing instrumentation for detecting viruses should be incorporated into standard operating procedures for flight and sample return missions.…”