Independent testing
The RMIT testing behind our mattress, in plain English
The top layer of every Sophie mattress is a foam called Hygroflex®. It was tested at RMIT University against four traditional memory foams. Here’s who ran that testing, what they measured, what they found — and, just as importantly, what it doesn’t tell you.
Whose test this is
Worth being straight about up front, because it changes how much weight the numbers deserve.
We didn’t commission this testing. We didn’t run it, we didn’t pay for it, and it is not a test of a Sleep Sophie mattress. The report was commissioned by Joyce Foam — the Australian manufacturer that makes Hygroflex — and carried out by RMIT University’s School of Engineering. We are a downstream buyer: we purchase Hygroflex from Joyce as an authorised reseller of their material and use it as the comfort layer in our four-layer Australian-made mattress.
That’s a limitation, and we’d rather state it than bury it. It’s also the reason the results are worth reading at all. A manufacturer testing its own product in its own lab tells you very little. A university engineering school running instrumented comparisons against four competing materials tells you considerably more — and RMIT had no stake in which foam came out ahead.
What was actually measured
Hygroflex was tested against four different traditional memory foams — five materials in total, put through the same instrumented comparisons:
- Pressure gradient
- How sharply pressure changes across the area in contact with the surface — whether load is spread out or concentrated into a few sharp points.
- Duration of pressure
- How the material behaves under sustained load rather than a momentary one. A foam can perform well for a few seconds and then bottom out.
- Immersion
- How far a body sinks into the surface before the foam starts pushing back.
- Envelopment
- How closely the material wraps around the shape pressing into it, rather than simply compressing beneath it. Immersion and envelopment sound alike and are not the same thing.
- Friction
- How much force it takes to slide across the surface — which is what changing position actually costs you.
These are measurements taken with instruments under controlled load. Nobody was asked how they felt about anything.
What they found
Four results, quoted exactly as they are stated to us. We don’t round them, combine them, or restate them as something bigger — and the “up to” is doing real work, so it stays.
| What was measured | Result, against traditional memory foam |
|---|---|
| Envelopment area, under a 75N load | Conforms to the body up to 67% better than traditional memory foam |
| Interface pressure, at 45% compression | Reduces pressure on the body up to 32% better than traditional memory foam |
| Heat dissipation | Dissipates heat up to 27% faster than traditional memory foam |
| Friction | Takes less than half the force to roll over or change position |
What those numbers mean when you’re lying on them
Envelopment, not immersion. Sinking into a mattress and being wrapped by one feel similar for about a minute and completely different by morning. Immersion is how deep you go. Envelopment is how well the surface follows the shape you actually are. A foam that scores well on envelopment supports the hollow of your waist and the back of your knees instead of leaving them unsupported while your hips and shoulders do the work.
Interface pressure. Your weight has to go somewhere. Spread across a wider area, no single point carries as much of it — which is the difference between waking up because your shoulder has gone numb and not waking up at all.
Heat. The oldest complaint about memory foam is that it sleeps hot, and it’s a fair complaint — dense foam traps warmth. This is the measurement that addresses it directly.
Friction — the one to pay attention to. Everyone shops for a mattress by lying still on it in a showroom, which tests almost nothing. You will change position dozens of times tonight. If each of those costs you real effort, that is a cost you pay every night for years. Less than half the force is the finding here, and on an adjustable base — where you are already moving the bed around you — it is the number that shows up most often in ordinary use.
Where the layer sits
Hygroflex is the top layer of four. The rest of the stack does its own job, and the RMIT figures describe the Hygroflex layer specifically — not the assembled mattress.
The full construction, sizes and what comes with each bed are on the electric adjustable beds page.
What this testing does not tell you
- It is a laboratory measurement of a material, not a clinical study. No one slept on anything.
- It does not measure sleep quality, pain, recovery, or any health outcome. It measures how a foam behaves under load.
- “Up to” means the best result observed across the comparisons — not a figure you should expect every night, and not a guarantee.
- The comparison was against traditional memory foam specifically. Not latex, not innerspring, not hybrid, not “all other mattresses.”
- It tested the Hygroflex® foam on its own — the top comfort layer — not an assembled Sophie mattress.
If anyone tells you a foam measurement means you will sleep better or hurt less, they have gone well past what the data supports. We’re not going to do that. What we will say is that the material under you is one of the few that has been measured independently at all, and that you can read the numbers yourself and decide what they’re worth.
Referencing this testing
If you’re an occupational therapist, a journalist, a student or a buyer checking our claims, these are the details of the underlying report:
- Report
- Evaluation of mechanical properties of a new foam material (Hygroflex foam) for medical mattress
- Reference
- AA-01-2018
- Institution
- RMIT University, School of Engineering — Sir Lawrence Wackett Aerospace Research Centre
- Commissioned by
- Joyce Foam, the manufacturer of Hygroflex®
- Sleep Sophie’s role
- Authorised reseller of the tested material. We did not commission, fund or conduct the testing.
The report is Joyce Foam’s property and covers their foam, so we don’t host a copy of it here. The summary above is our own description of publicly stated methodology and results. Spotted something we’ve represented incorrectly? Tell us and we’ll correct it. How we fact-check everything else on this site is set out in our editorial standards.
Numbers are easy to print. Come and feel it.
Book a demo and roll over on one yourself — that's the test that actually settles it.
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