Another hidden gem: the polypropylene those centrifuge tubes are made from transmit IR frequencies opening up several sensor possibilities.  PIR detection through the housing reaches about 5m for people. The loggers can also be triggered by animal traffic, so pet behavior is a popular theme for final student projects.

https://thecavepearlproject.org/2023/12/01/the-e360-a-classroom-data-logger-for-science/