MIT chemists have printed carbon nanotubes on paper to create a sensor for detecting dangerous gases. The lines are printed on specially treated paper. When an electrical current is passed through the paper, the change in resistance indicates gas molecules that have bound to the printed nanotubes (and hence, the presence of the chemical). The test sensor detected small traces of ammonia gas but researchers believe it will work for almost any type of gas.
The nanotubes are powdered carbon nanotubes (tiny cylinders of rolled up carbon sheets) compressed into pencil lead.
“You can’t imagine a more stable formulation. The molecules are immobilized.”
MIT hopes to create “drawn” sensors that can detect ethane levels in order to monitor fruit for ripeness before being shipped or stored. They also believe the print method could be used to develop cheap monitors for sulfur compounds that would assist homes in the detection of dangerous natural gas leaks.
