Medical Plastics News web content editor Ian Bolland recently spoke to Dr Colin Grant, an SPM sales & applications specialist at Hitachi’s scanning electron microscope lab, to find out how the firm’s latest technology can benefit medical device manufacturers.
Microscope
‘Almost idiot proof’ was how Dr Colin Grant described the ease of operation of the Hitachi AFM 5500M microscope when Medical Plastics News was invited to the Daresbury lab to see the role that the new product can have in the medical device industry.
Given the right, and relatively straightforward training, he is a believer that Hitachi’s microscopic technology for analysing can be operated from someone who may regard themselves as a novice previously.
“Where the Hitachi brand stands out is that it is fully automated,” Dr Grant explained, “It literally is click, load, image.”
Automation appears to be the USP of Hitachi’s microscope as it has been designed for ease of use when it comes to analysing the surface of any type of material.
“I know in Japan these types of things are really good for semi-conductor industries where surfaces really are absolutely critical. It’s used quite predominantly in pharmaceuticals, quite a lot in automotive, imaging, aerospace. Anywhere where you’ve got a surface that is actually quite critical”, Dr Grant added.
Surfacing, of course, isn’t out of place in the world of manufacturing medical devices, as well as medical grade plastics.
Quality control is a big part of what these microscopes can do, while there is also the advantage of not needing to be an advanced user.
The microscopes can allow for analysis of the characterisation of its material properties, for example, its strength, elasticity, its stiffness. It can allow a surface to be scanned, poked and measured for electrical currents – with Dr Grant saying this an area of interest for researchers in life sciences.
This includes comparing materials, being able to examine materials if they have failed in any way, process evaluation, as well as the ability to identify any kind contamination or if corrosion features on the materials.
“Yes, you can be an advanced user but if you need to know a surface, what it looks like, its roughness value, I think anyone could learn how to use one of these fairly quickly. You don’t need a physics degree, you don’t need a PhD, any technician would be able to grasp this pretty quickly.
“If manufacturers need to understand the characteristics of their surfaces (topography, roughness, mechanical properties etc.) or require a degree of quality control – at high resolution (i.e. between the micro and nano-scale) – then the atomic force microscopy (AFM) technique might provide them solutions.
“Our system has key benefits as it is fully automated, so anyone from lab technicians to advanced research professors can use it.”
Not all materials are the same and not all manufacturers want their materials to be at the same temperature, as specifications vary from manufacturer to manufacturer, but the Hitachi microscope allows for analysis for individual manufacturers to tailor their needs.
Dr Grant added: “There are other techniques around but, in essence, this is probably one of the most high-precision, highly accurate quantitative metrology measurement instruments available really.”
The Hitachi microscopes show a way to measure very small film thickness, and the various domain sizes. One analysis seen by Medical Plastics News also showed the ISO standard roughness measurements that accompanied the analysis of polymer blend surfaces.
The microscope itself could work on its own for a long period of time, with the automatic features allowing work to take place out of hours and be ready for analysis when returning to the working day.
As for the surface of any material, the analysis that can be provided by the AFM5500 can illustrate the roughness or smoothness of a surface in a 3D format. For the sporting aficionados, it’s not dissimilar to watching golf on the television and being forgiven for thinking that the course is a little flatter than usual – but if you were to watch it at the course itself, the slopes, hills and obstacles are then on show to appreciate how difficult it is to play 18 holes in 70 or fewer shots.
With his background in academic research, Dr Grant explained that a field of research he and his academic colleagues are interested involves making small grooves within plastic to allow for the material to prevent bacteria getting inside or below the surface, if the application was protective packaging, for example.
He explained that one of the research projects included making polymer surfaces like a saw tooth, with grooves in order to prevent any bacterial infiltration or contamination as much as possible. Though not foolproof, it’s an intriguing development in the academic world.
“The distances here are in the order of about one to two microns so really, really small. The idea here is that they’re antimicrobial; because if you narrow the size of this, the bacteria would not be able to get in and it wouldn’t want to stay on top, it couldn’t get in between.
“Preferably it sticks elsewhere, it’s not completely foolproof – some bacteria would not be able to stick down to these surfaces. There are various different plastics where I think microscopy does come in where you’ve got some structure to your surface.”
There is also room for exploring how polymers will react under different temperatures and whether the material is suitable for the manufacturer to use.
“In terms of research and development, different polymers have different melting temperatures, so if you use a different melting temperature what does the end product look like?
“It becomes more unique when you consider that this type of microscope can operate at a range of temperatures, in vacuum, in air, humidity, aqueous conditions. It can be adapted to the conditions of use for the product – or to test the limits or boundaries of the chosen materials in these environmental conditions.”