The solution involves wrapping the arm in a braid made of hollow silicone tubes, and then pumping something like an epoxy into the braided structure to solidify it into a hard cast.
Cast21, the company setup by the students and the name they’ve given to their casting technology, may offer the benefits that 3D printed casts promise but without the time consuming effort of building them for each patient.
Cast21 would be applied by a clinician who would choose a size, from a selection of casts that best fits the patient. Once a fit is found, a solidifying liquid is delivered into the hollow inside of the casts’s braids. The arm is then kept perfectly still for about twenty minutes to let the cast get hard, after which it’s ready to go into the world.
It should be washable, breathable, and, maybe most importantly, the skin below scratchable.