How do the sleep sensors in latest Mac laptops work? On older Mac laptops, placing a magnet near the steep sensors sleeps the Mac.  However, on newer Macs, putting magnets on the sleep sensors won't sleep Mac, such as closing the lid does.

How do sleep sensors work then? I did many tests with different laptops (12", 13" 2016/2017) etc.. I know where the sensors are, but they won't sleep the Mac, not even putting a magnet on each sensor.
Sleep sensors are typically Hall Effect sensors. You can consult this PDF that Apple produces for case manufacturers which illustrates where the sensors are located per device. The PDF is titled: Accessory Design
Guidelines for Apple Devices.

Make sure you're using the correct polarity when orienting the magnet(s) over the sensors, this is likely why they're not working as you're expecting.

References


Trick reveals all 102 hidden magnets in the 2018 iPad Pro