The nerve gas sarin was released on several subway lines in Tokyo in 1995 in a terrorist attack. Thirteen people died, and many more had severe injuries. But while such an incident is going on, how do you determine what’s happening and what might be in the air?
Someday, first responders might come onto the scene and, after evacuating everyone, release a bunch of beetles with tiny, thin sensors on them into the subway stations. As the beetles make their way into the stations, the sensors would wirelessly report back whether sarin gas or some other agent is present.
That’s what Jang-Ung Parkand colleagues envision. They are developing futuristic thin, flexible electronic devices that could attach onto leaves, insects, clothes or human skin to monitor environmental conditions or even someone’s health status.
They are using carbon-based materials — graphite and carbon nanotubes — instead of silicon, which is traditionally used to make electronic circuits.
“The fabrication and processing can be much cheaper with our sensors because the entire device can be chemically synthesized in a single step, and carbon is also much less expensive than silicon,” says Park.
Silicon-based electronics are brittle and rigid, but the carbon-based sensors that Park’s team is making are flexible. The sensors can even bend around a thin optical fiber without breaking. They also can stick to living things, like skin, bugs and plants, without adding an adhesive.
They tested their sensors by putting them onto the leaf of a “lucky bamboo” plant and onto the backs of “stag beetles.” The sensors performed well, detecting DMMP, which is similar to sarin, within seconds.
The authors acknowledge funding from the Basic Science Research Program of the National Research Foundation of Korea, IT R&D Program, Materials Original Technology Program and Technology Innovation Program.
What do you think? Is this feasible? What other applications can you think of for these sensors, aside from detecting harmful gases?
“In-situ Synthesis of Carbon Nanotube–Graphite Electronic Devices and Their Integrations onto Surfaces of Live Plants and Insects”