Types of Scanning Electron Microscopes

The Scanning Electron Microscope (SEM) is an established tool, revealing the world of nano-meter resolution to researchers for many decades since its commercialization in the mid-1960s. In this time, the SEM has evolved to cover a range of systems and the right choice of SEM can boost both your analysis capabilities and your laboratory’s performance.

For lab managers, choosing the right SEM for your facility can seem confusing. There are a lot of different factors to take into account and, in this blog post, we examine one of the most fundamental decision points: should you opt for a Floor Model SEM or a Desktop SEM?

Scanning Electron Microscopes are broadly divided into two categories: Floor Models (or full-size SEMs) and Desktop SEMs. To identify the right option for your laboratory, you must factor in the upfront cost, ongoing operational and maintenance costs, size, performance, applications of your proposed system, and your end-users.

In the simplest terms, Desktop SEMs are usually smaller and simpler systems, costing less and used for general applications. Floor Model SEMs are larger and more complex, costing more and used for more specialized applications.

While Desktop SEMs may initially seem like a cost-effective and obvious solution, a Floor Model SEM may provide a better, long-term investment thanks to several unique features. Let’s deep dive into some key scanning electron microscope characteristics now and investigate what each type of SEM can offer your laboratory.

When it comes to the initial cost, Desktop SEMs are usually priced lower than Floor Model SEMs, with reduced ongoing operational and maintenance expenses. However, there are significant overlaps in the price ranges. The Axia ChemiSEM and Prisma E SEM floor models, for example, are both excellent entry-level models.

A Floor Model SEM often requires a dedicated room to house this specialist piece of kit, with a larger footprint than a Desktop SEM. A Floor Model SEM may require additional infrastructure and space, such as environmental isolation facilities. There’s also a human cost factor to take into account, where some Floor Model SEMs may require a specialist operator, which could present additional staff training or recruitment costs.

In summary: a Desktop SEM is a cheaper option compared to a Floor Model in terms of the upfront cost and ongoing operational and maintenance expenditure.

Cost is not the only consideration. Floor Model SEMs offer superior resolution to Desktop SEMs.

Floor Model SEMs can resolve features down to the sub-nanometer length scale. They provide details on surface topology especially on sensitive samples such as polymers or nanoparticles, that other imaging systems are simply not capable of. Our powerful Verios XHR SEM, for example, is capable of sub-nanometer resolutions from 1 to 30 keV. Our Apreo 2 SEM system provides all-around nanometer or sub-nanometer resolution performance on materials ranging from nanomaterials, powders, catalysts, and nanodevices to bulk magnetic samples. Simply put, these are more powerful and specialized systems than their Desktop counterparts.

Desktop SEMs offer a lower resolution but still achieve impressive results. Our Phenom Desktop SEM range is capable of resolutions of the order of 15 nm and less, for example, and our Phenom Pharos Desktop SEM can achieve resolutions of up to 2.5 nm.

In summary: a Floor Model provides superior resolutions compared to a Desktop SEM, providing sub-nanometer resolutions.

Desktop SEMs are simpler to operate, in comparison to Floor Model SEMs, and you can often obtain an image by simply pushing a couple of buttons. The Thermo Scientific Phenom product line, requires minimal sample preparation and reduced vacuum requirements, providing the speed, ease-of-use, and performance for many applications where novice users can obtain an image within minutes.

However, you may be limited in terms of what you can achieve with a Desktop SEM, depending on your primary application.

Floor model SEMs offer the flexibility and versatility to meet a wide range of academic and industrial needs. They can support large and heavy samples, come with a comprehensive range of accessories, excellent imaging quality for the most challenging materials or the smallest details, and dynamic experimentation. Our Prisma E and Quattro floor models, for example, are both environmental SEMs (ESEMs). This means you can study materials in their natural state. The Axia ChemiSEM model also offers live, quantitive elemental analysis, making it a popular option for materials research, quality control, and process control applications.

Floor Model SEMs are now providing consistently better user experiences too, using techniques such as automation to lower the barriers of use for these machines. For example, the majority of our machines use our exclusive ChemiSEM Technology for energy dispersive spectroscopy (EDS) analysis. This is a powerful and integrated technique, which provides you with the tools to conduct qualitative and quantitative micro-scale chemical composition analyses – from one user interface.

In summary: a Desktop SEM is simple to use but often limited for certain applications. Floor Model SEMs can meet a wide range of academic and industrial needs.

If you’d like to find out more, click here to speak to one of our expert team today.

To summarize, Desktop SEMs provide you with quick results, ease of use, and a small footprint. Floor Model SEMs provide flexibility and high performance. They are capable of working with large and difficult samples and come with a range of accessories to meet your exact requirements. Floor Model SEMs also provide superior resolution and the best contrast, compared to Desk Model SEMs.

However, a SEM is a major investment for any laboratory and it’s important to select the right system for your specific requirements. There’s no one-size-fits-all solution and we recommend getting specialist advice before you make such an important purchase. It’s important to evaluate each system based on your requirements, including the scanning electron microscope specifications and scanning electron microscope characteristics that are important to you and your applications.

At Thermo Fisher Scientific, we’ve been developing industry-leading SEMs for decades. We offer a range of versatile tools, including everything from our easy-to-use Thermo Scientific Phenom Desktop SEMs to powerhouse instruments capable of unparalleled resolution and contrast like the Thermo Scientific Verios SEM. If you’d like to find out more, contact one of our expert team today.