A Self-Destructible Device That Decomposes Through Reactions With Water
The idea of a self-destructible device that has a pre-recorded message that goes “This tape will self-destruct in five seconds” as soon as you switch it up sounds straight out of a cool, tech savvy detective action movie does it not?
But thanks to a bunch of scientists from the University of Houston and China, this is now reality.
The researchers have produced electronic devices that gradually decompose through reactions with water in the air. They believe the device could have important applications not just in security but in environmental protection and potentially medicine too.
The work holds promise for eco-friendly disposable personal electronics and biomedical devices that dissolve within the body. There are also defense applications, including devices that can be programmed to dissolve in order to safeguard sensitive information, said Cunjiang Yu, Bill D. Cook Assistant Professor of mechanical engineering at the University of Houston and lead author of the paper.
Undoubtedly, with electronic devices becoming ever more widesprea
d, interest has grown in ‘transient electronics’, which would do their job and then decompose. The field currently requires immersion in aqueous corrosive solutions or biofluids. Yu said this work demonstrates a completely new working mechanism – the dissolution is triggered by ambient moisture. Which means that a biomedical implant could be programmed to disappear when its task – delivering medication, for example – is complete. Sensitive communications could be devised to literally vanish once the message was delivered.The researchers deposited materials common in the semiconductor industry, such as copper, magnesium oxide and indium gallium zinc oxide semiconductors, onto a polyanhydride substrate. Gradually, water vapour from the air hydrolysed the polymer’s anhydride groups, causing decomposition of the film. The carboxylic acid produced by the hydrolysis could break down electronic materials too. The researchers fabricated transient resistors, capacitors, transistors and other electronic components. The decomposition time could be varied from days to weeks and potentially even longer by altering the polymer’s anhydride content and the humidity. Yu suggests this could be achieved in real-world devices using packaging.
John Rogers of Northwestern University, US, is impressed. “It introduces the notion that you can use the substrate as the vehicle for triggering physical disintegration and dissolution of the electronics. That’s a new concept in transient electronics, which I believe is emerging as a pretty important technology.” He suspects that the acidity, as well as the probable rapidity of hydrolysis in the moist environment of the body, may hinder biomedical uses, but he believes military applications are possible. “Ultimately, for those systems, the idea of a triggered transience is the holy grail,” he says. “But a system like Cunjiang’s, in which a timer is built into the material dictating how long it will exist, is interesting.”
