Researchers from Switzerland’s engineering, science, technology, mathematics and management university ETH Zurich have developed a device 3D printed from a special polymer that is capable of differentiating short sound waves from longer sound waves. This will allow only the object’s edges to be detected and would be applicable in areas that only need a limited amount of detail or information. The next step for researchers is to try the sound detection method using shorter wavelengths of ultrasound and other forms of inaudible sounds. You can read more about this 3D printed device over on 3DPrint.com: http://3dprint.com/96871/3d-printed-sound-edge-detect/