In the near future, it might become possible to carry out medical surgeries without having to cut the skin open; all thanks to researchers at Duke University and Harvard Medical School. In a new proof of concept published Thursday (Dec 7) in Science, they demonstrated a 3D printer that uses ultrasound to print biomaterials inside an organ. The researchers behind the path-breaking technology are Junjie Yao, a bioengineer at Duke University; and his co-primary investigator Yu Shrike Zhang. Many 3D printing technologies utilise light to solidify ink into structures, often requiring printing on surfaces. This poses challenges for creating minimally invasive structures, as surgery is typically necessary for implantation. “That’s really the limit of current bioprinting technology,” said Yao. So, the researchers came up with the idea to make a printer that uses ultrasound waves which travel deeper through opaque materials.