This article demonstrates how researchers at the Penn State University cleanly downsized a standard glass microscope slide using the LatticeAx and eliminated more than a day of extra work, although the exclusively prepared slide was too tall to fit in their AFM.
Being a shared-use facility, the Materials Research Institute (MRI) at Penn State University offers analytical and materials imaging services for the industry and for University research. Dr Trevor Clark, team leader of electron microscopy at the Institute’s Materials Characterization Lab, was completing an analytical service project for a local company which required characterization data on a newly developed set of fibers for submission to a regulatory agency.
Clark’s team had just finished compiling size, structure, and other data with the help of the scanning electron microscope (SEM time, ~4 hours) when the customer received a request from the regulatory agency for additional characterization of the morphology of the fiber — but this time with the help of the Atomic Force Microscope (AFM).
The researchers used the SEM for an additional three hours to identify the most appropriate fibers for AFM, and then began the process of preparing the selected samples for AFM characterization. Considerable time (~4 hours) was spent on sample preparation, where the individual fibers were placed on and adhered well to a glass slide using a double-sided tape and strong glue, as shown in Figure 1. The tips of the fiber were exposed on each side, and it was possible to easily separate each fiber for individual characterization. The slide with the fibers was now ready to be mounted in the AFM holder. Yet, with the height needed to accommodate the fibers, the glass slide was too tall to fit in the holder.
Figure 1. A diagram of the slide showing how the samples were mounted. The slide needed to be downsized to fit the AFM holder, without damaging the fibers that were already carefully selected and mounted.
Due to this height constraint, the researchers considered their options. It was thought that reducing the size of this cautiously prepared slide was not possible because a traditional scribing and cleaving process damages the edge with glass shard and surface-contaminating particles. It seemed that the only available option would be to do the entire process of sample preparation again; however, this would need a lot of time. The specific fibers most appropriate for the AFM had already been established with the help of SEM; redoing this and all of the steps would be obviously a setback.
The microline indentation method of the LatticeAx allowed us to reduce the glass slide’s size to the exact height we needed, in just seconds and without generating dust particles on our sample. This time savings and cleanly cleaved surface were critical to our project.
Dr Trevor Clark, Microscopy Team Leader
LatticeAx Cleaving Machine
Clark learned that a LatticeAx cleaving machine was set up at the University in the cleanroom of the Nanofabrication Lab. He assumed that if the cleanroom would accept, it could probably be used to cleanly downsize the glass slide and without producing particles, thereby allowing the characterization of the fibers to move forward with a higher speed rather than repeating the entire sample preparation process.
The opportunity turned out to be successful, saving the researchers days of time to prepare and re-characterize one more set of fiber samples. The glass slide with the prepared fibers was positioned on the LatticeAx 420 cleaving system and a controlled, shallow, microline indent was created on the glass slide at the specific point where the cleave was needed to downsize the slide to the desired dimension. A solution to their challenge was found quickly — within a few seconds. The cautiously prepared samples stayed intact on the slide, and it was possible to fit the slide into the holder for the AFM characterization.
Figure 2. Glass slides cleaved using the LatticeAx. The scribeless cleave process of the LatticeAx eliminates generation of dust particles, making it ideal for downsizing the glass slide that already contained unique, proprietary fibers.
Advantages of LatticeAx
Above all, the LatticeAx’s scribeless cleave process was totally dust free. When Clark first conceived the concept of employing handheld tools for scribing the glass side, his biggest worry was that scribing would bring in unwanted dust particles to the delicate fiber samples already positioned on the slide.
Clark was overwhelmed by the exceptional cleanliness and speed of the LatticeAx, and also the ease with which the desired area could be cleaved. The Electron Microscopy Lab is a core, shared facility that manages an extensive collection of samples, some with complex preparation requirements. Therefore, a machine like the LatticeAx — which can be easily learned and employed, and also can repeatedly provide the preferred results — is a real asset to a facility with many users having different levels of experience.
Moreover, Clark considers the LatticeAx as a key instrument for some Focused Ion Beam (FIB) users since it has the ability to reduce the amount of FIB supplies as well as the time required to prepare target areas for imaging and analysis. He is eager to further investigate the applications in which the LatticeAx can assist his users in reducing the amount of time required to prepare samples, while allowing the characterization process to be started with cleaved samples of the highest quality.
This information has been sourced, reviewed and adapted from materials provided by LatticeGear.
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