Zac Vawter made history this past weekend by climbing the 103-story Willis Tower in Chicago with a mind-controlled bionic leg.

The robotic leg was developed by a team lead by the Rehabilitation Institute of Chicago's (RIC) Center for Bionic Medicine. The RIC specializes in bionic limbs, and in 2005 successfully developed bionic arms for an amputee named Jesse Sullivan that were able to be controlled with his mind like normal limbs. 

The $8 million project was funded Department of Defense’s Army Telemedicine and Advanced Technology Research Center. 

Vawter was able to complete the feat in just 53 minutes and 9 seconds. In a statement to The Verge, Vawter discussed the advancement of his bionic leg compared to a prosthetic leg: "I have to take every step with my good foot first and sort of lift or drag the prosthetic leg up. With the bionic leg, it’s simple, I take stairs like I used to, and can even take two at a time."

[The Verge via Associated Press]