Cyclists competing in the Tour de France weren't the only thing hitting the pavement during the race.
Thousands of inspiring messages raising cancer awareness were being painted on the road in bright yellow lettering by a robot created by Carnegie Mellon alums.
The messages were submitted to the 'Chalkbot' via texts and Twitter. For each message "chalked" on the road, the robot sent a photo of it along with GPS coordinates back to the sender. (Watch video.)
"These were more than names, these were messages to lost loved ones and survivors," said Nathan Martin (A'99), whose Pittsburgh-based company Deeplocal helped design the software. "To walk behind Chalkbot and see each message forced me, personally, to feel the impact that cancer is having on people."
Still lingering in his mind: a message that read "Mom I wanted to take you here" and another from the widow of a friend that Martin himself lost to cancer earlier this year.
Chalkbot was built by Standard Robot, another Pittsburgh-based company with a Carnegie Mellon tie, founded by Greg Baltus (A'97).
The machine is a computer-controlled airless paint sprayer. An array of 48 pneumatically-actuated spray guns are supplied high-pressure paint by a custom hydraulic-pump system. An onboard computer actuates the pneumatic valves which, in turn, actuate the spray guns.
A second computer contains the queue of the messages received through Twitter, also known as tweets. That computer sends the onboard computer high level commands and controls the onboard camera which takes a picture of each chalked tweet. The photos are then processed and forwarded to the sender of the tweet.
While in France, Baltus learned a family member was diagnosed with breast cancer.
"This, along with printing thousands of messages to and from people impacted by cancer, gave me an eye opening awareness of cancer's reach," he said.
Chalkbot was part of the Livestrong campaign founded by U.S. cyclist and cancer survivor Lance Armstrong for cancer research.