Part of the gun that the police believe was used to kill the C.E.O. of UnitedHealthcare was made by a 3D printer using a popular design found online. By Thomas Gibbons-Neff and Aric Toler At first ...

The team has developed a procedure to 3D print a soft and flexible replica of a patient's heart. They can then control the replica's action to mimic that patient's blood-pumping ability.