Here’s your task. Build a tiny sensor that detects a signature of infrared (IR) wavelengths characteristic of a hot tailpipe, a wood fire, or perhaps even a human being. Design the sensor so that it can remain dormant and unattended but always alert, even for years, without drawing on battery power. And build the sensor so that the act of detection itself can initiate the emission of a signal that alerts warfighters, firefighters, or others that a “signal-of-interest” has been detected. It’s just the sort of intelligence, reconnaissance, and surveillance (ISR) technology that can increase situational awareness while minimizing the need for potentially dangerous maintenance missions to replace run-down batteries.
Sensor awakens only in the presence of a signal of interest