MicroscopyPioneers
camera, during the summers from 1965 to 1967 (Figure 2). Dr. Allard still has these movies. He remembers this time as “more fun than a man should have.” Some of this work was published in Proceedings of the Electron Microscope Society of America (EMSA). Upon graduation from the University of Michigan
with a BS in Science Engineering, Allard began his doc- toral research at Michigan. In 1969 he received notice that he was being drafted into the military. Fortunately, Allard had passed his qualifying exams, and Michigan awarded him a master’s degree in metallurgical engineer- ing. The draft board also recognized his expertise, so he was allowed to fulfill his service working on classified projects at the ORGDP involving gas reactions for ura- nium isotope separation processes. After completing his service requirement Allard returned to the University of Michigan to complete his doctoral research, which he did in 1981. Connections made during his service would lead him back to Oak Ridge in 1986 for a position in the new High TemperatureMaterials Laboratory. In 2006 Dr. Allard was thinking about a new experi-
mental thrust for his newly installed JEOL 2200FS aber- ration-corrected microscope, and his thoughts returned to in situ gas reactions. Serendipitously, a week aſter pro- posing the idea to his manager, he received a call from John Damiano and David Nackashi of Protochips who were interested in advancing the utility of their microelec- tromechanical systems (MEMS)-based heating devices (E-chips) for in situ electron microscopy studies. Unable to contain his excitement, Dr. Allard declared, “Boy have you come to the right guy!” Te feeling was instantly mutual, as his collaborators appreciated his ability to boldly push boundaries without recklessness. Allard and Bigelow began a lasting collaboration with the team at Protochips. Bigelow was responsible for the initial holder design and construction [1]. With the aim of building a closed-cell system that for all microscopes,
would be universal the team began
with a 3-chip configuration with the middle chip serving as the heating element. Tey quickly learned this could be reduced to a more efficient and slimmer 2-chip design and still retain the closed nature, where the top chip acts both as the heater and seals the environment [2]. Aſter several itera- tions, the holder permits tilt up to 18 degrees to allow x-ray collection and thereby “operando” in situ experiments. It is impressive to think of the strides made by Dr. Allard and his colleagues and even more so to think of the improve- ments since the earliest experiments in 1965. It speaks to Dr. Allard’s willingness to experiment and test new ideas, that in under a decade the initial simple heating holder evolved into a refined design with high-tilt capabilities for operando experiments. Dr. Allard ref lected on the improvements, and
speaking of the first iteration, “We took enamel-coated copper wires and scraped the enamel off the ends to contact the gold electrodes on the MEMS E-chip. It was
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early on just serendipity that we were able to assemble it, seal the cell, heat it, and maintain the vacuum of the column.” Ref lecting on the system built for the experi- ments in the 1960s, he noted about how vibrations from the motor drive of the camera limited the magnification they could use and, ultimately, the resolution to ∼20 Å on a good day. In the beginning stages of his EM career with Prof.
Bigelow, despite all of the limitations—tungsten filaments burning out every few days, a bulky noise-inducing camera teetering on the edge of vacuum requirements—Dr. Allard tinkered, built, and pioneered the world of microscopy into the dawn of in situ ultrastructural research. Now, in the later years of his career, with old and new collaborators, he has brought us into the age of gas cell in situ. With these innovations we are now able to explore those important questions where before-and-aſter imaging won’t suffice. Dr. Allard credits luck for his experiences and collabora- tions in the development of the in situ gas cell. However, it is perhaps more accurate to say his successes are a result of his willingness to walk through the figurative and literal open doors of electron microscopy.
References [1] Allard et al., Microscopy Res & Tech 72(3) (2009) 208–15.
[2] Allard et al., Microsc Microanal 18(2) (2012) 655–56.
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