Pencil draws gas sensors on paper

In the past, the University of Illinois at Urbana-Champaign has used nano-ink (made up of silver nanoparticles), which allows users to draw electrical circuits on paper. Massachusetts Institute of Technology (MIT) chemists continue to create a pencil-like device that is capable of drawing gas sensors on paper to identify harmful gases. environment.

Today, carbon nanotubes have been used in various chemical sensors. However, to make such sensors, the nanotubes must be dissolved in a toxic solvent such as dichlorobenzene. This process is potentially dangerous, which can damage the nervous system and sometimes not work.

The MIT team has found a safer way to create chemical sensors without resorting to toxic solvents. It compresses the carbon nanotube powder into a solid like graphite and uses it as the "gut" of writing. They use this writing on gold paper, lead spots will form gas sensors.

The first goal the technology aimed at was to identify ammonia, a colorless gas, commonly used in agriculture and industry, which, according to US officials, could become a poison if it falls into the hands of terrorists. Its advantage is that ammonia gas will stick to nanomaterials if they come in contact with the paper. To identify other gases, scientists simply add metal atoms on nanomaterials or wrap around other materials.

Experts say gas sensors made of new technology can be used in food technology, health care and security.