Medical Services An on-the-job Penn Medicine nurse shows her donated 3D-printed face shield created by volunteer army personnel. Soldiers with the 20th Chemical, Biological, Radiological, Nuclear and Explosive Command have joined other volunteers in the Aberdeen Proving Ground, Md., area to volunteer their free time and personal 3D printing capabilities to print and create face masks for donation to hospitals and health care workers across the Nation combating COVID-19. SHARE IMAGE: Download Image: Full Size (1.22 MB) Photo By: Rebecca Nappi, Army VIRIN: 200510-A-HF386-1010M.JPG Photo Gallery