3D Printing for Prosthetics

One increasingly popular design application is 3D printing. Additive manufacturing or 3D printing is the process of making a three-dimensional solid object from a digital model. 3D printing is achieved using an additive process where successive layers of material are laid down in different shapes to create an overall object. This process makes 3D printing distinct from other machining techniques that rely on the removal of material by subtractive processes such as cutting or drilling. As a result, this technology has grown in popularity since the start of the 21st century and has led to a manufacturing revolution. 3D printing is now used in a wide range of fields such as industrial design, architecture, engineering and construction, medical industries, and many others. Bespoke Innovations is one example of a company that uses 3D printing to fulfill their mission.


A Bespoke Fairing

Bespoke Innovations is part of a movement towards individualized medicine.They create personalized Fairings to bring more humanity to people who have congenital or traumatic limb loss. They do this using 3D technology. Scott Summit the founder of Bespoke Innovations said, “Our efforts have been to connect additive manufacturing solutions to the people who stand to benefit from them the most. We look forward to new innovations coming from 3D Systems to further enable these developments.” The company is using advances in 3D printing to create prosthetic limb casings wrapped in embroidered leather, shimmering metal or whatever else someone might want. Summit stressed, “I wanted to create a leg that had a level of humanity. It’s unfortunate that people have had a product that’s such a major part of their lives that was so under-designed.” Bespoke Fairings are specialized coverings that surround an existing prosthetic leg, accurately recreating the body form through a process that uses three-dimensional scanning to capture the unique leg shape. These Fairings not only return the lost contour, they invite an expression of personality and individuality that has never before been possible.

deb_5527_FPO_0Fairings are made with the help of 3D Technology. First an image-based 3D scanning technology is used to capture images of both the “sound side” leg and the prosthetic leg. A 3D computer model results, and a mirrored “sound side” leg is then superimposed over the prosthetic leg. This way, the users are given their body symmetry back, at least to the greatest possible extent. In the case of Bilateral amputees a “stand-in” close to their original or preferred shape can be used. Then the customization of the Fairing is directed by the user, allowing them to completely control the personalization process. After the design is complete the Fairing can then be printed. 3D printing has allowed Bespoke Innovations to build something based on the unique shape of the user, modify it with their designs, and then turn it into something physical that can be worn. The resulting products are flexible, durable, and lightweight. The entire process can simply be summed up as scan, design, and print procedure (click on the links to view videos of each process). Overall, additive manufacturing or 3D printing has led to many innovative applications, such as the Bespoke Fairing.

The Solar Cooker: A Sustainable Design

Sustainable design, according to the website ecolife.com, is “the intention to reduce or completely eliminate negative environmental impacts through thoughtful designs.” Often referred to as environmental design, this concept can be applied to various different categories of design. Regardless of the application, however, a sustainable design will try to include certain environmentally-friendly outcomes such as lowering energy and water usage, reducing green house gas emissions, limiting resource consumption by using renewable resources or recycled materials, reducing or eliminating waste products by reusing or recycling them when available, and using non-toxic materials or those that will contribute to human health. A fine example of a sustainable design is the solar cooker.


Throughout the world, people have limited access to cooking fuels. In fact, in developing countries electricity and gas are out of the question when it comes to cooking. Only firewood and charcoal are within reach, and charcoal can sometimes be too expensive to purchase. That only leaves wood, and in developing countries trees are sometimes scarce. It takes a lot of wood to cook an entire meal for a family every day, and what few wood sources there are continue to dwindle. Families often have to walk miles to get firewood, and they often end up spending what little money they have on fuel, leaving less to buy food with. This shortage of cooking fuels results in illness and in a lot of cases death. In fact, 2 million people die every year from bacterial illnesses that could have been prevented by pasteurizing drinking water or food. Fires also release a lot of pollutants into the air. This smoke, filled with particulates, is bad for the environment and for the people who breathe them in. Inhaling smoke and soot often results in both lung and heart disease and an estimated 1.5 million people die from smoke inhalation annually. The use of wood for kitchen fires also creates a local deforestation problem, which destroys animal habitats and other ecosystem functions.

This is where the sustainable design of the solar cooker comes into play. There are two different types of solar cookers: the box cooker and the parabolic cooker.  The box cooker uses a shiny metal on the lid to direct sunlight into a dark pot or box, which absorbs the energy and turns it into heat. A glass covering over the box may be used to create a green house effect that allows sunlight to enter but keeps the heat from escaping. This design allows the solar cooker to reach temperatures high enough to pasteurize food and water, which is around 180 degrees F. In fact, the box cooker can reach up to 300 degrees F, and can cook food in a couple of hours.



The parabolic cooker can get even hotter, reaching temperatures up to 400 degrees F. This design is slightly more complicated. It uses curved reflective surfaces to focus a lot of light on a relatively small area. A pot of food sits in the arm of the cooker which suspends it in the middle of the reflective surfaces directly where all the light is concentrated.


The solar cooker uses sunlight, a renewable resource, to heat food or water to the necessary levels of pasteurization. This design greatly improves the health of individuals living in developing countries by killing bacteria in water or food. Also, the cooker eliminates the need for an open flame which means cleaner, safer air free from the particulates that cause lung and heart disease. The solar cooker also reduces firewood usage which protects animal habits and other ecosystem functions. In fact, using a solar cooker for an entire year can eliminate up to 1 ton of firewood. The solar cooker is a great example of a sustainable design that limits resource consumption by using a renewable resource, minimizes impact on the local ecosystem due to the decrease in firewood usage, and uses non-toxic materials that contribute to human health by eliminating the smoke particulates that cause lung and heart disease.

Prosthetics: A Design for Human Variability

Adaptive technology is any object or system that is specifically designed for the purpose of increasing or maintaining the capabilities of people with disabilities. Prosthetic limbs are a fine example of such an adaptive technology. While rare, limb amputations have become increasingly common worldwide. Often times, this kind of amputation leaves the victim with the inability to perform necessary daily tasks due to reduced functionality. In an effort to recover the lost functionality, a prosthetic limb can be fitted to the person. Until recently, the benefits from such prosthetics were often outweighed by the burden of their use or  attachment to the body. However, new prosthetic limbs have been developed which dramatically increased functionality and in some cases actually overtake the utility of biological limbs. These prosthetics have allowed users to live a productive and normal lifestyle free from limitations. In fact, specialized prosthetics have even been made to allow patients to participate in sports and recreation.

pistorius-feature-525The “Cheetah Leg” is optimized for sprinting. The prosthetic is built from carbon fiber and can boast a high strength at about half the weight of a biological leg. The decreased weight requires less torque to swing forward. This allows for faster rotation with less exertion. The shape of the leg acts as a spring, which stores energy on the heel strike and releases it at the toe-off. The length of the prosthetic also increases the stride of the runner in relation to their height. Overall, the performance of the limb is remarkable for a prosthetic and may even surpass that of a normal leg. In fact, the Cheetah Leg has become a topic of debate in the Olympics due to its possible advantage.

flipperFor marine situations, a promising prototype is the “Neptune” flipper. The Neptune is configurable for above and below the knee amputations. The purpose of the Neptune is for balancing the power of the leg kicks of uni-lateral amputations. Also, for bi-lateral amputations, two Neptune flippers could be used to add power to the swim stroke. Since the majority of amputations are due to health conditions, the flipper could allow users to exercise after their surgery. The initiation of a health routine could prevent further limb amputations, and improve the health of the patient.

KONICA MINOLTA DIGITAL CAMERAProsthetics have also been developed for winter sports. Although a walking-limb can be modified and used, a ski-specific alignment should be performed for the duration of the activity. Additional foot dorsiflexion and external knee support should be added. For advanced users specialty feet, which eliminate the boot, are available. The plantar surface of the ski foot can be modeled after the boot sole and attached directly to the ski bindings eliminating the boot altogether. This eliminates excess weight, but, more importantly, enhances energy transfer to the sporting equipment for more efficient performance. Individuals with uni-lateral amputations will usually opt to use a single ski with modified bi-lateral forearm outriggers. Recently, a  prosthetic has been designed specifically for sports that require a loaded, flexed knee position, such as snowboarding. Snowboarders are in bi-lateral dynamic hip, knee and ankle flexion as they negotiate the hill. This new knee is adjustable and produces the weighted knee flexion needed to snowboard successfully. No additional adaptive gear is necessary when using the energy-storing knee.

Recent research efforts have propelled protheses design from century-old devices that were uncomfortable to wear to technically advanced devices. The functionality of the new devices is approaching that of the original limb and, in some instances, surpassing it. These prosthetics have given patients the opportunity to perform daily functions and live a normal lifestyle not limited by the functionality of their prosthetic. Prosthetic limbs are a model example of an adaptive technology.