3D-printed Exo-prosthetic leg by William Root


There are more than two million amputees in the United States and 90 percent of these involve amputations of the lower limbs. Although the standard prosthetic technology do help the patients to regain most of the functionality they have lost, they are quite expensive. These prostheses are expensive as they require specialized labor to customize them individually for different patients and this involves a lot of complexity. Also, their mechanical and robotic look and feel can have a negative effect on the psychological wellbeing of some amputees.

Industrial designer William Root’s Exo-Prosthetic leg takes into consideration the significance of beauty in prosthesis design. According to him, the unaesthetic appearance of prosthetic limbs is due to the flawed and outdated process involved in producing them. His Exo-Prosthetic leg looks to modern technologies to modernize the manufacturing process. According to Root, by using 3D scanning, 3D printing and modeling software, the whole process can be programmed to make a customizable, inexpensive and attractive product.

First, the person’s residual limb and remaining intact limb (if present) are scanned to build the exact 3D virtual model, thereby allowing to match up within fractions of a millimeter. During this process, a technology developed by a lab at MIT captures leg tissue properties allowing a better fit and also better comfort between the socket and the residual limb. After this, a new model of the prosthesis is created by combining the scans of the intact leg, residual limb and the prosthetic mechanisms in a 3D mesh model.


Later, to reduce weight, the limb is hollowed out forming an exoskeleton. The surface pattern of the exoskeleton is customized with patterns and colors to suit the client. After this, the finished model will be sent to a 3D printer where it will be printed of a durable and lightweight metal – titanium. Titanium dust particles will be fused together using laser sintering. Then Exo-leg is assembled using a standard pyramid connector.

Exo takes on the form of the wearer’s own body and this creates a more human and intimate connection for them. The next stage is developing a fully functional prototype and determining the structural requirements. The Exo has received a lot of interest and currently Root is considering how best to apply the new method to existing systems.

Via: Designboom