Implantable medical devices, such as artificial joints, coronary stents, and artificial organs increasingly are customized for individual patients using 3D printing technologies. After surgical implantation of externally printed devices, the soft tissue surrounding the implant or repaired bone must heal on its own. This process can result in disfiguration and debilitating scar tissue. Short-term implants provide temporary tissue support to assist the healing process, but eventually require surgical removal.

The proposed invention facilitates printing soft structures inside the body. Heat-enabled cross-linking polymers are inserted into a body cavity as a liquid and then activated with heat, causing them to solidify. The polymers conform to a specific shape creating 3D soft structures directly in the body. The technology could repair soft tissue damage, as well as create reconstructive implants or antennae for improved transmissivity.