Dynamical jamming might sound like the latest music craze to hit Clark University, but it’s actually cutting-edge technology that one day might enhance the fit of prosthetic limbs.
Arshad Kudrolli, professor of physics at Clark, is working in conjunction with Harvard University colleague Chris Rycroft to determine what kinds of granular materials will make a prosthetic limb most comfortable for wear. The research team is investigating whether “dynamically jammed” materials, which are not of uniform shape and size and therefore fit together at odd angles, supply more durability as they are locked together under pressure. The researchers hope their experiments will lead to the creation of a more comfortable pad that fits between a person’s natural limb and their prosthetic.
“The idea is that the more jumbled they are, the better they will hold their strength,” Kudrolli says of the dynamically jammed particles. “If the material is jammed better, then you can put more stress on it, and it will hold its shape for a longer period of time.”
Fitting a prosthetic limb is a “very individualistic” process, says Kudrolli, who notes that making a pad for a prosthetic limb is not unlike creating a gel insert for a shoe. Very basically, the chamber of the pad is filled with material and then all the air is evacuated. The remaining material offers support, cushioning, stability and comfort.
However, the very softness of a gel that makes a sneaker insert feel so welcome can actually give a prosthetic pad a looser, and therefore less stable, fit. Kudrolli and his team are experimenting with the perfect placement of other filler materials, which are often unpredictable when they are packed together. “On one hand you can have rougher shapes, and they can lock and have strength,” he says. “On the other hand, angular particles may not pack as well.”
The team is now seeking funding for the next round of research. “Clearly, there is a lot to be learned, but this has many potential applications,” he says. “It’s basic research that can be used.”
As Kudrolli says, while the effects are not always immediate, the progress is nonetheless remarkable. “This isn’t as direct as saving someone’s life, but what we do has a wide impact. As a physicist, it’s my job to think more broadly.”