MAKING COMPLICATED SIMPLE

Thoughts on improving ease of use of XPS instruments

Considering the complexity of a modern smart phone, it is staggeringly easy to use.?I’m sure it’s hard to remember a first encounter with a touch sensitive screen but it undoubtedly seemed intuitive.?The tap of a finger to select, pick up and drag.?The swipe left or swipe up to scroll.?The pinch of thumb and forefinger to magnify or demagnify.?All these actions to navigate and initiate processes, often with simple icons for guidance.?Even though I struggle to remember my first encounter, I can distinctly remember my then 4-year-old daughter happily mimicking what she’s seen me do so that she could watch Peppa Pig on my phone.?

And I’m pretty sure that I’ve never opened, let alone read, a User manual for my smart phone, despite its functionality and complexity.

Which leads to the thought ‘should analytical instruments have a similarly low barrier to entry?’?It’s a fact that the AXIS Supra+, with its full automation, is significantly easier to operate than the manual, ‘home-built’ system I learnt on three decades ago.?It’s easy to forget the old potentiostat, with jittery needle display, used to apply the acceleration voltage to the X-ray anode.?It actually felt as though you were applying a high voltage, rather than the abstract double digits of a software readback that we’re used to today.?

There is undoubtedly a growing trend.?Analytical instruments are becoming easier to use, approaching ‘smart phone’ type simplicity that any novice can walk up to and run.?But where does that leave the analytical scientist??

Analytical instruments are becoming easier to use, but where does that leave the analytical scientist?        

As James Strachan highlights in his recent editorial of The Analytical Scientist [1], there are certain advantages to opening up analytical techniques to many more researchers.?He continues ‘there is a big gap between the cutting-edge and the truly accessible—and this middle ground must not become an open but confused playing field’.?

As a manufacturer of XPS instruments we are acutely aware of our role in lowering the barrier to entry for use of the modern spectrometer.?It is true that there has not necessarily been a step change in the ease of use.?Over several generations of spectrometer, the level of automation and therefore ease of use has increased.?Our current generation of spectrometer, the AXIS Supra+, is fully automated, from sample handling to gas admission for ion sputtering.?Complete automation means that the spectrometer can be operated remotely from another room, site or even continent.?It also means that the spectrometer is easier to operate for the novice User.?Automation has great advantage in increasing sample throughput, lowering the cost of ownership when measured against the number of samples analysed.?But, to quote Bill Gates ‘automation applied to an inefficient operation will magnify the inefficiency’ or to paraphrase ‘garbage-in, garbage-out’.

Having established that we can reduce complexity through hardware automation, what other support can be provided to the analyst??A growing area within analytical instrumentation is the incorporation of AI, artificial intelligence.?Applying this to XPS surface analysis is still some way off, but the fundamentals exist and are available in the latest release of acquisition software.?Robust peak identification with a high degree of confidence in peak assignment is a non-trivial requirement, forming the starting point for any sample analysis.?Improved computer derived peak identification from unknown samples minimises User error or bias.?It also forms the starting point in an automated sample analysis workflow, known in Kratos’ ESCApe as Data-dependent Analysis (DDA).?This acquisition method identifies peaks in a survey spectrum and then acquires high resolution, narrow region spectra from the major components.?We know from our recent User survey that 89% of our Users regularly employ the large area survey acquisition mode as the starting point for sample analysis.?For an experienced analyst DDA can simply be considered a time-saving acquisition method.?For the inexperienced analyst it provides confidence that elements will be correctly identified and appropriate high-resolution spectra acquired.??

A further step in guiding analysis, simplifying spectral acquisition and interpretation in ESCApe is the use of the Known-Sample Workflow (KSW) method.?As the name suggests, a standard acquisition is progressed to allow charge correction and fitting of pre-defined component models to narrow region spectra.?This type of analysis is only appropriate for well-known, highly reproducible samples and currently finds primary use in QA and QC type application.

Data dependent acquisition and known sample workflow methods will not replace the knowledge of an experienced analytical scientist.?Indeed, the concept of an ‘expert system’ is not a new one.?Dr Jim Castle has championed this concept in the early 2000’s [2].?Over two decades later, the analyst is still probably the single-most important component for materials characterisation.?Dr Castle identifies the starting point in creating an expert system as the setting of goals, a series of steps leading to the reasonable outcome for the analytical investigation.?This is analogous to the discussion between the subject specialist, usually the owner of the sample, and the analytical scientist responsible for using the spectrometer for the sample analysis.?Knowledge and experience of the capabilities of the XPS instrument are fundamentally important for successful sample analysis.

It seems therefore that whilst the data acquisition has been simplified by instrument automation there is still no replacement for the detailed knowledge held by expert analytical scientists.?There remains a responsibility of both manufacturer and User of the XPS instrument to educate.?The education needs to be balanced between XPS application, understanding the information available from the technique and correct use of the instrument to acquire that data, and XPS fundamentals, understanding how to analyse the data generated from the instrument.?As Strachan concludes in the Analytical Scientist [1], through education we ensure that the next generation of XPS Users have the skills and knowledge to apply and, perhaps more importantly, critically assess the latest generation of instruments provided by manufacturers.?

In making the complicated simple, it’s important to remember that the expert analyst must in fact struggle with the complexities and embrace the simplicities.

references

[1]?J. Strachan.?Will you play upon this HPLC??The Analytical Scientist Dec.2022?https://theanalyticalscientist.com/issues/1222