- Why Scratch Resistance Matters for Gaming Mouse Feet
- How Scratch Resistance Works
- How Scratch Resistant is Sapphire?
- Hardness of Sapphire vs. Glass
- Hardness of Sapphire vs. Ceramic
- Sapphire vs. Gorilla Glass Victus
- The Case for Sapphire Mouse Feet
There is much debate about the gliding qualities of various mouse feet. Part of this discussion is subjective and comes down to personal preference. The other part of it, which is in regards to how low the level of friction is, is dependent on many factors and requires a boundary condition of a surface pairing in order to quantify.
This is part of the reason we don't make claims arguing that SAPPHIRESKATES are the "best" mouse feet.
There is one area in which we can claim to be the best and that is scratch resistance. (See for yourself at 8:02 in my video here: https://youtu.be/NP03nIvWIXw?t=482)
Why Scratch Resistance Matters for Gaming Mouse Feet
Scratches have an incredibly dramatic impact on friction that often goes overlooked. Take this study as an example:
AlMotasem, A T., Bergström, J., Gåård, A., Krakhmalev, P., Holleboom, T J. (2017) Atomistic insights on the wear/friction behavior of nanocrystalline ferrite during nanoscratching as revealed by molecular dynamics Tribology letters, 65(3): 101 https://doi.org/10.1007/s11249-017-0876-y
The scratch distance corresponds to the size of the scratch in angstroms, a unit that is equivalent to 0.1 nanometers. Increasing the scratch distance from zero to a mere 50 angstrom increases the friction coefficient by many orders of magnitude. The fact that a scratch the size of a mere half a nanometer can have this effect is surprising.
How Scratch Resistance Works
Before we talk about how scratch resistance works, we need to define "what is a scratch". A common definition in physics is when a "surface permanently deforms or yields". However, do understand that the term is not even precisely defined in science. That is why in many physics studies, you see more specific terms used such as fracturing, shearing, or a description of the depth of deformations.
Let's bring it back to discussion about gaming mice though: what happens when you glide your mouse across a soft mousepad? Does the mousepad get scratched? Why is it cloth in the first place? The answer is elasticity: a soft mousepad is elastic. When an object moves across it, it creates temporary displacement. This is known as "elastic deformation".
Now, consider what happens when you take a knife and gently rub it on your phone's screen? There's a good chance no scratches will occur at all. Gorilla Glass is chosen over a material like sapphire for its flexibility which helps significantly to prevent cracking as it allows for elastic deformation to occur (I used to use sapphire screen protectors which is a far less elastic material. The problem was that they broke all the time. I'll explain later why this isn't an issue for SAPPHIRESKATES).
Okay, now press a bit harder with the blade on the phone's screen. You will have created a mark that is basically impossible to remove. You just created what is known as plastic deformation. The surface has permanently deformed, thus creating a scratch.
The meaning of scratch resistance can be explained by both the amount of force required to create these permanent deformations, in addition to its resilience when encountering another material of a different hardness. Scratch resistance is dependent on how strong the forces are that hold the material together and is directly connected to hardness.
How Scratch Resistant is Sapphire?
The most popular scale for representing scratch-resistance is the Mohs Hardness Scale. It's certainly not the best measurement, but it has its purpose and is easy to understand. The general principle is that if you rub two different materials together, the one that is left with scratches is the softer material. The unscratched material therefore scores higher on the Mohs Hardness Scale.
A diamond is the hardest material (aside from some theoretical exotic materials) and sits on top of the Mohs hardness scale with a rating of 10. (At this point, you might be wondering: "what about diamond mouse skates?" and as a side note: here's my answer. We've looked into it and tested it, but were unable to determine if friction was lower than sapphire, and the cost would be exorbitant. Not ruling it out yet though).
Sapphire has a Mohs hardness of 9. This is extremely high and there's a very low chance you will encounter a harder material. Note: we do also make moissanite mouse skates (for the flex, for their incredibly brilliant beauty, and since they slightly edge out sapphire with a Moh's hardness of 9.5).
Hardness of Sapphire vs. Glass
Glass has a Moh's hardness of about 5.5. Aluminosilicate glass, which is what Pulsar uses in their glass mouse skates, has a hardness of up to 7 on the Mohs scale, which is quite high for glass. The Mohs scale is not linear though. Sapphire is roughly twice as hard as aluminosilicate glass and roughly 3 times harder than standard glass.
Hardness of Sapphire vs. Ceramic
People often ask me to make comparisons of SAPPHIRESKATES vs. ceramic skates. From my own rudimentary tests, ceramic skates, such as Lexip, have both excellent low-friction properties and high hardness. There's a problem though: and I'm not talking about these mouse skates themselves, but rather the term "ceramic". This term is highly generic and can refer to truly any number of materials. Oxford dictionary says that ceramic is: "made of clay and hardened by heat."
In this industry, ceramic is referring to something else. But generally people understand it as a hard and durable material. It's also something that can be cast from a mold, simplifying the manufacturing process significantly compared to sapphire.
We don't know exactly what materials go into ceramic that is used for mouse feet. But there's a good chance that Aluminum Oxide (Al2O3) is one of these materials. And sapphire is made of just Aluminum Oxide.
Ceramics are polycrystalline by nature, and the same is true for most materials. You can think of glass as crushed up bits of sand. Some industrial ceramics are likely to have crushed up bits of sapphire. Everything is melted down so that the structure of the material is arranged randomly, yet is homogenous.
On the other hand, sapphire by definition is single-crystal (monocrystalline). There are some truly unique properties that you get from using something made from a single crystal.
To conclude on the point of ceramic hardness: there's no answer as to how scratch-resistant ceramics are in general, since they can be made from various materials. But ceramic mouse skates likely fall somewhere in between glass and sapphire in terms of hardness.
Sapphire vs. Gorilla Glass Victus
As far as I know, there aren't mouse skates made of gorilla glass. But I wanted to mention Gorilla Glass in this article since it's a material that we interact with on a daily basis. As mentioned previously, I think that sapphire doesn't make a great material for a smartphone screen. Apple and other companies were considering sapphire screens but abandoned the idea when realizing that the screens were more prone to shattering. I've gone through over 3 sapphire screen protectors, and trust me, I loved the smooth glide for mobile gaming, but in the end they broke even after small drops.
The thing with smartphone glass is that it must be incredibly thin: just 0.2-0.3mm. They also need to prioritize anti-cracking over anti-scratching. A cracked screen presents a dangerous hazard for its user. A scratch is a mere nuisance.
SAPPHIRESKATES aren't going to risk accidental drops that can incur cracking. But will encounter many things that would otherwise scratch them if they weren't made out of sapphire. We have also found that the extra thickness of sapphireskates compared to a sapphire screen makes them quite resilient and difficult to crack as well. When using a cloth pad or plastic pad, I am confident that you will never crack a piece of SAPPHIRESKATES (even if you are playing Warzone, top 10, final circle, and encounter a rage-hacker which causes you to slam your mouse.)
Going back to the comparison of Gorilla Glass: I looked into Gorilla Glass Victus because it represents the latest and greatest from Corning. In their spec sheet, they list the hardness of 590 kgf/mm2 (kilogram-force per square millimeter) using the Vickers Hardness scale. Using this same measurement, sapphire has a hardness of 2200 kgf/mm2, about 3.7 times higher than Gorilla Glass Victus.
Again, this is by design: Corning wants to make their Gorilla Glass less prone to drops and shattering. Allowing a bit of elastic deformation is critical to this design goal for smartphone displays.
The Case for Sapphire Mouse Feet
To conclude, sapphire is over twice as scratch-resistant over the next most scratch-resistant mice feet on the market. Sapphire is roughly 458 times harder than PTFE, which is an extremely soft material that is meant to be used disposably and replaced after wearing out.
When starting this company, I wanted to use the best possible material for mouse feet. Ruby Sapphire has been used as the bearings inside mechanical watches for over 300 years due to the fact that they do not require lubrication and don't need to be constantly replaced.
I would argue that using SAPPHIRESKATES will certainly save you time compared to using PTFE, glass, and even ceramic skates which are still prone to scratching. I certainly wouldn't go so far as to say that SAPPHIRESKATES are the best mouse feet. But the most scratch-resistant? Yes.