Whether we like to admit it or not, we’re all creatures of habit to some extent.
When we’re shopping for example it makes life easier to go to the store we’re most familiar with and the brands we recognise. The same is true when purchasing AFM probes. It’s just easier to get the ones you’ve always bought from the place you’ve always got them from. And if they are working well for you then that’s great.
However, there are some key triggers to be aware of that suggest a new probe supplier is worth investigating…
You start imaging new types of samples with your machine.
These might be different from a topographic point of view - e.g. you might have a sample with more extreme structures on it; or the surface properties might be different – e.g. the hydrophobicity of the surface or whether there are different adhesion properties.
If the new samples have more extreme height variations, perhaps with steep sidewalls, you may need a probe with a high aspect ratio (HAR) tip to better resolve these structures. If the surface exhibits greater static charge, you may need to look at using a highly doped or even conductive probe to reduce the effect of the charge on the tip-sample interaction. Or maybe you’re seeing large adhesion between tip and sample, so a choosing a probe with a stiffer cantilever (higher spring constant) may help to overcome these additional forces.
If your lead time on probe supply becomes problematic.
If you’re having to wait a long time for the delivery of your usual probes then that could be a good moment to check out other suppliers. There can be large variations in lead times, depending on where probe manufacturers hold their stock and where they ship from.
We are all too aware that often probes need to be shipped ‘yesterday’ – sometimes those all-important experiments can’t wait! Unfortunately, we can’t ship back in time, but we are shipping to our UK and European customers within 48 hours in most cases.
If the service you receive from your supplier has dropped off.
You don’t have to put up with poor service from your probe provider because that’s where the AFM instrument manufacture recommends you get your probes from - support around probe choice often comes a distant 2nd place compared to support and advice on the instrument. It is unlikely that they are the only probes that will work with your instrument and your samples. Alternative probe providers will be only too happy to spend some time with you, understanding your needs and assessing whether their probes can do the job you require.
If you are concerned about the storage lifetime of probes in Gel-Paks®
The jury is still out as to whether storing your probes on a gel material for any length of time does actually lead to any contamination of the tip surface.
However, if this is a concern for you it’s worth investigating how different probe manufacturers operate. At NuNano we keep our wafers in a cleanroom environment and sealed until required. In most cases they are only transferred into a Gel-Pak® a few days before being shipped.
We can also set up scheduled shipments (a bit like HP ink!). You let us know how many probes you need and how often and we ship to schedule, giving you peace of mind that when they arrive with you they’ve had a minimum amount of time in the Gel-Pak®.
Getting an AFM probe expert in to take a look at how you’re running things can be enormously useful. We can advise on the probes will work best with your requirements and help with the configuration of your probes and your machine. If you’re interested in having a chat to me about any of this please do get in touch james@nunano.com or call our office on +44 117 2993093
(Gel-Pak® is a registered trademark of Delphon).
For more tips from AFM users check out these blogs: 5 top tips for effective AFM imaging: a beginners guide, From one AFM user to another …, 5 more top tips for effective AFM imaging: the intermediate guide