Microtomy for TEM and SPM

Ultramicrotomy is an obvious example of a preparation method developed by biologists and 

Recently, microwave techniques have been used for more rapid embedding [109-113], and 

Trimming a block to a specific shape and size is more critical for TEM and SPM than for OM. The cured specimen block is cut close to the specimen plane with a jeweler s saw or a razor blade. The pretrimmed block in a microtome chuck is placed in a holder built to fit in the stage of a stereomicroscope. The top surface is cut or faced and then the sides of the block are cut at an oblique angle to provide a trapezoidal shaped block face. Where possible, the epoxy is all trimmed away where this is not possible, a minimum sized block face with little epoxy is prepared. Smaller block faces are better for TEM. The bottom of the section, the part that will be cut by the knife first, should be the longer side of the trapezoid. Block faces on the order of250pm or less help to minimize chatter artifacts that are readily imaged by SPM. 

Developments have been made to reduce the compression of ultrathin sections by use of an oscillating diamond knife [118]. A prototype of this oscillating diamond knife was evaluated and tested to prepare ultrathin sections for comparison with the same sample prepared with a 35° angle diamond knife [119], as shown in Fig. 4.10 of a blend of polypropylene and polyethylene. A block face from such sectioning should be flatter and be more useful for AFM imaging as well. 

Plummer [120] provided an excellent review in his reflections on the use of microtomy for materials science specimen preparation, with a table of material classes, references, and comments. The review includes examples of polymer composites, blends, membranes, elastomers, and coatings. Kink bands and shear deformation were shown in polybenzobisoxazole (PBO) fibers microtomed and studied by TEM [121]. Fibers treated to cause compressive deformation were taped to sheet polycarbonate and coated with spray acrylic to fix them to the substrate. Small sections ( 5mm) attached to the polycarbonate were cut, trimmed, and microtomed to a thickness of 40-80nm with a new area of a diamond knife and picked up on 400 mesh grids. Ericson and Lindberg [122] showed that when the sample holder of the 

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