Tony Stark never imagined his bionic suit would earn the superhero title of “Iron Man” (because technically, the suit is titanium alloy).

Tyler Petresky, director of resource management at Limbitless Solutions, also never imagined his bionic prosthetic arm would gather the attention of millions.

Petresky, a sophomore at University of Central Florida, is one of the 40 members on the Limbitless team who helped build an “Iron Man” themed arm for a 7-year-old boy named Alex Pring, who was born with a partially developed limb. After eight months of development and redesign, Alex received his new arm from the Iron Man himself, Robert Downey Jr.

As a part of the Collective Project, Microsoft filmed the interaction between Alex and the Avengers actor. Since its release, the video has gone viral.

Limbitless Solutions is a nonprofit organization run by students at the University of Central Florida. Started last May by Albert Manero, the goal of the organization is to make affordable, 3-D-printed bionic limbs for children with amputations. Alex’s “Iron Man” arm was the first arm by Limbitless.

The arm works via surface electromyography, Manero told The Washington Post in an e-mail.  Electromyography (EMG) reads the electrical signal from the brain and transmits it to the arm, producing a signal that triggers the opening and closing of the hand.

According to the organization’s Web site, the “designs are considered bionic because they are controlled directly by the child, with the EMG pads providing a direct control and interface for the arms.”

“To make an arm, a child is first measured (size of residual limb, length of limb, etc.) and the current model of the arm is then appropriately scaled,” the organization explains. “From there, minor tweaks to the design may be necessary to accommodate any features unique to that child’s condition, and then the arm is printed. From there the pieces are assembled and the electronics are wired together and set in place. Finally, the child must be fitted with the arm and an appropriate socket, and the EMG sensors are calibrated before the arm is ready for use.” 

Creating a prosthetic bionic arm takes anywhere from 30-50 hours of work, including 3-D printing, assembly and testing. According to the Web site, three to six people are involved in the creation of each arm.

“Alex’s arm is 3-D printed on a Stratasys printer, which takes approximately 40 to 50 hours to manufacture,” Manero said. “Assembly and the electronics take some additional time. Each arm is uniquely tailored for the user, both in fit and in expression.”

The average prosthetic limb costs around $40,000.

Alex’s “Iron Man” arm cost less than $350 in materials, with the research and development time contributed.

Manero said he was inspired by Ivan Owen, a special effects artist and puppeteer in Bellingham, Wash., who developed the first 3-D printed hand. Owen posted his design and instructions on Thingiverse, an online community to share 3-D designs.

In the future, expect to see bionic legs, assistive wheel chair technology, leg bracing and exoskeleton suits from Manero and his team.

“We will keep advancing the technology to help those in need,” Manero said. “And look to work with the VA for temporary solutions for veterans and the UN and UNICEF to support kids around the world.”

Actor Robert Downey Jr., posing as his "Iron Man" alter ego Tony Stark, gave a 3D-printed bionic arm to a 7-year-old boy born with a partially developed limb. (Reuters)