DARPA (Defense Advanced Research Projects Agency) has awarded a $3.5 million contract to IBM for its Vanishing Programmable Resources (VAPR) project, which aims to create “transient” electronics that can "disappear" remotely. Here you see a chip dissolving into water droplets.
Large distributed networks of sensors will be able to function for a limited time before the chips destroy themselves. An RF signal will be used to initiate the chip’s disintegration into mere powder.
DARPA mentioned that “IBM plans is to utilize the property of strained glass substrates to shatter as the driving force to reduce attached CMOS chips into Si and SiO2 powder.”