Hello everyone!
I am designing a waterproof robot. The robot has a 10 watt IR LED (730nm-740nm) and a thermal imaging camera. I am essentially going to drill a hole for each item in the plastic container/hull and mount the devices inside the container. The diameter of the hole for the LED is about 1 inch and the diameter of the hole for the thermal camera is about 1/4 inch. I obviously don't want any water to come in contact with the LED or the thermal camera or to come into the robot's hull. So I was planning on gluing/waterproofing some material over the holes. I want the material to be transparent for each device. What type of material would be best for the IR LED and what material would be best for the thermal camera?
Thank you for your help!
What sort of thermal imaging camera?
Materials that are transparent to short wave IR (750 nm) and "body temperature" IR (10,000 nm) are completely different. Pure germanium is often used in the latter case.
Overview on IR-transparent materials
Do you expect the thermal imaging camera to work underwater?
I ma using this thermal camera SparkFun IR Array Breakout - 55 Degree FOV, MLX90640 (Qwiic) - SEN-14844 - SparkFun Electronics.
The robot is designed to drive on land and to float on top of water and be a boat. Is a flat germanium "window" even feasible for the thermal camera?
To locate germanium window suppliers, start here.
Do you intend that the IR LED act as a floodlight for the camera? If so, does the camera even see 740 nm light? I doubt it, but could not find any information on the Melexis 90640 detector response spectrum. The data sheet is silent on the issue.
So the IR LED is a flood light for a raspberry pi camera which is for visible light.