Tuning frictional behavior on the fly has been a long-standing engineering dream. This new insight into how surface geometry governs slip pulses paves the way for tunable frictional metamaterials that can transition from low-friction to high-grip states on demand.
The system, tested in prototype form by NPR at the company's headquarters, consists of fairly standard-looking sneakers with a carbon fiber plate running through the soles. These sneakers are attached at the back to close-fitting, 3D-printed titanium leg shells that cinch to the calves. The battery-powered contraptions, containing complex motors, sensors and circuitry, weigh a couple of pounds and look like something out of Terminator or RoboCop.
Rather than waiting until you arrive in a ski village or going out of your way to drive into the mountains, Boot Solutions is introducing a process in which you simply scan your feet and they do all the fitting remotely. Overall it seems pretty simple. You use the Boot Solutions app on on your phone to take a medical grade 3D scan of both feet and the company offers you plans from there.
Squeaking occurs across various contexts including shoes, bike brakes, rubber tires, and biomedical implants when soft and hard surfaces contact each other. Researchers used high-speed photography to study a rubber block sliding across hard acrylic to identify the source of these sounds. The investigation revealed that pulses similar to earthquake dynamics drive the squeaking phenomenon.
We were not expecting to find so much richness and depth from a physics point of view underneath the sole of a shoe, says Adel Djellouli, a scientist at Harvard University and co-lead of the study. In a new study, scientists explore the physics that give rise to the familiar squeak of basketball shoes sliding on a hard surface.
The midsole of the Nimbus 28 is slightly softer than the 27 but it's not very noticeable. The 28 midsole is also more sculpted and more streamlined which is how they managed to reduce the weight. The 28 is 7% lighter than the 27.
Puma PUMA MagMax Nitro 2 Verdict The PUMA MagMax 2 is a good max-stack daily trainer with deep cushioning and a moderately bouncy ride. Version 2 gets rid of the annoying poking arch and has a tweaked midsole that's more energetic. I was impressed with the updates made to the MagMax 2; however, there are similarly priced competitors with even more energetic rides. Daily training
The Brooks Adrenaline GTS reaches a major milestone in 2025 with the release of its 25th edition. Outside of the ASICS Kayano, it's hard to think of another stability trainer that has remained in production for this long. That longevity speaks to a shoe built on a strong foundation, one that has continued to evolve over the years while maintaining its place as one of the best-selling stability shoes on the market.
The Hyperion Elite 5 has a midsole made entirely of DNA Gold, a PEBA foam. It's the foam with the highest level of energy return of all the Brooks midsole foams. The Hyperion Max 3 has a dual-density midsole with a top layer of DNA Gold and a bottom layer of DNA Flash, an EVA foam. The firmer DNA Flash provides a stable, durable base. Both shoes have plates in their midsoles but the Hyperion Elite 5 has a stiff carbon plate while the Hyperion Max 3 has a flexible nylon plate.
Specifically, the company is focusing on the production of its newest, weirdest shoe-a giant soled laceless running shoe with a single-piece toe box made of "hyper-foam" plastics sprayed on by robot arms. The plastics are 40 percent biofoam, and the shoe is made of just eight pieces; On says its minimalist approach saves on the shoe's carbon footprint.