Just a few months ago, we told you about a really interesting metamaterials project developed by a team of researchers at Germany's Hasso-Plattner Institute (HPI). The researchers created a 3D printed working door handle using metamaterials, without a single moving part inside and 3D printed in one piece. Building on their 3D printed door latch and metamaterials research, the team is back again, and this time created a 3D printed, PIN-protected door lock. This was obviously a little more complicated than their original latch, but their work has shown that it's possible to secure a door without circuits and electronics. Read more at 3DPrint.com: http://3dprint.com/167295/metamateri...int-door-lock/