Gregory Gallinat of Excelitas Technologies (a Veritas company), demonstrates their new DigiPile Thermopile Detector proximity sensor, ultra small consuming only 10 microamps, would for example enable a future smartphone to detect presence to turn itself on (not even need to touch the device like in the Moto X).

You can read more about these sensors here: http://www.excelitas.com/pages/product/Thermopile-Detectors-Sensors-and-Array-Modules.aspx