"Wrapping a broken or fractured arm in two kilos of clunky, soon to be smelly and itchy, plaster in this day seemed archaic to me," Mr Evill said in an earlier interview with APNZ.
His radical solution involved using data from both X-rays and a 3D scan of the patient's fracture to create a custom-made cast.
The cast is printed using a 3D printer and creates a snug, breathable fit.
The spiderweb-like membrane means the waterproof cast is well ventilated, and printed reinforcements mean the cast is strongest where the bone is broken.
Mr Evill, who grew up in Nelson and studied design at Victoria University of Wellington recently moved to London.
He received almost $7000 for winning the New Zealand leg of the James Dyson Award and another $19,000 as a runner-up in the 18-country competition.
A battery powered upper-body robotic arm which instantly increases human strength beat more than 500 entries to win the top prize.
Augmenting arm strength by 18kg, Titan Arm helps rehabilitate people with back injuries, allowing them to rebuild muscle and re-learn motor control. The exoskeleton technology also aids those lifting heavy objects as part of their daily work.
A team of mechanical engineering students from the University of Pennsylvania spent eight months creating Titan Arm. Their $53,000 prize would fund further development, testing and, ultimately, commercialisation. The team also aimed to use 3D printing techniques to tailor-make the arm for users.
The other runner-up was Handie, an affordable prosthetic hand with sensors that can read brain signal using a smartphone to compute the electrical impulses on the skin's surface, also utilising 3D printing technology.