In The Dark Knight, Lucius Fox shows Bruce Wayne a neat bit of memory weave fabric. In its resting state, it is a light, flexible material, but when an electrical current is applied, it pops into a pre-programmed shape. That shape could be a tent or a bat-themed paraglider. Science has not caught up to Hollywood in this regard, but the concept has been demonstrated in a material which increases its rigidity up to 318% within one second when placed in a magnetic field. Those numbers do not mean a lot by themselves, but increasing rigidity in a reversible, non-chemical way is noteworthy.
The high-level explanation is that hollow tubes are 3D printed and filled with magnetorheological fluid which becomes more viscous in the presence of a magnet because the ferrous suspended particles bunch up to form chains instead of sliding over one another. Imagine a bike tire filled with gel, and when you need a little extra traction the tire becomes softer, but when you are cruising on a paved trail, the tire becomes as hard as a train wheel to reduce friction. That could be darn handy in more places than building a fast bike.
Car suspension.
https://en.wikipedia.org/wiki/Magnetorheological_damper
“Spadaccini believes that FRMMs could be used as variable stiffness joints in soft robotics and could be integrated into smart wearables that are flexible in the absence of a magnetic field and then change properties to absorb an impact or vibration when an incoming threat is sensed” what,
like falling onto a giant magnet,?
Or you integrate the magnet in the system, at such distance that impact would only make it close enough to trigger said proximity effects.
Wow, that sounds really wearable…..
> In its resting state, it is a light, flexible material, but when an electrical current is applied, it pops into a pre-programmed shape.
Ever heard of Shape-memory alloy (e.g. Nitinol aka ”muscle wire”)? Heat that up by current and it’ll return to its shape.
https://en.wikipedia.org/wiki/Shape-memory_alloy
Yes we have but it isn’t a light, flexible material.
Correcting myself: apparently very thin threads of Nitinol can be quite flexible, making a fabric of such threads may be close enough?
Having worked a bit with nitinol wire, experimenting to achieve exactly what you describe, they become too hot for any practical wearable purpose…
Imagine a bike tire that picks up every random bit of ferrous scrap laying about and then when the circuit is broken flings it off in all directions. FUN!
“Pedestrians in the bike lane? Not anymore with ElectroTire™!”
**Fenders not included.