Researchers at TsingHua University in China presented an alternative way of transplantable biomedical devices by directly printing three-dimensional (3D) medical electronics inside the biological body through sequential injections of biocompatible packaging material and conductive liquid metal ink. All the complex 3-D electronics is fabricated by using the clinical syringe as the injection tool. Firstly,a 10 ml syringe with 5 ml packaging material solution (mass fraction of 25.0%) is filled and then vertically inject the solution into the target region at a rate of 1 ml/s.