I was reading a MEMs handbook when I thought
school kids textbooks could have a little MEMS item typically less than a millimeter radius that tells how many times the book has been used during a particular period
the capacitive version of a mems movement sensor could affect an RC circuit attached
to one of those RFID [] things to describe on visiting the classroom how many times the book had been studied
Technologically that is: possibly a tiny photovoltaic plus an RC circuit where the capacitor was associated with a capacative MEMS sensor; the RC circuit modifies the impedance of the RFID which is basically a coil
I'm skipping the transistor as the idea is to have it function absent a battery
Teachers could use this to urge different study habits to their students as may be beneficial
Even just flipping through the book to "look compliant" might result n actual textbook reading; If the MEMS item was twice as costly to produce as an RFID[] then that would be cheaper than a quarter
thus this thing which is cheaper than a quarter might cause a tenth better study habits which might translate to tens of thousands of more college students