Richard van As, who lost his own fingers in an accident, developed the 3D-printed prosthesis called Robohand.
"I can pick up stuff," Liam says in a Robohand video. "I can throw a ball."
The subject of an Indiegogo fundraising campaign, Robohand has so far helped four children in South Africa.
"I'm excited to try cricket, golf, and go swimming with it," he says.
"It's fun to have, awesome. And I can do almost everything with it," he says. "My friends think it's awesome."