Researchers have developed an artificial nose that is sensitive enough to diagnose head and neck cancer (HNC) through breath analysis.
An array of functionalized membrane-type surface stress sensors (MSS) distinguishes people with cancer through a signature response to breath samples, according to a phys.org story.
Researchers from Switzerland and Japan developed portable, no-invasive cancer detection units that use conventional piezoresistive cantilever devices. Chemicals coated on cantilevers absorb specific compounds, causing deflection of the cantilevers. These deflections can be measured through the change in electrical resistance at piezoresistors, but the piezoresistive cantilever-type sensors have limited sensitivity.
Recently, comprehensive structural optimization has led to an MSS that results in significant improvement in sensitivity and stability. The MSS is made from a thin silicon membrane (typically 2.5-µm thick and 500 µm in diameter), suspended by four piezoresistive beams attached to the circumference.
The researchers fabricated an array of MSS and coated them with different polymers to absorb various chemical compounds in breath samples. Their research showed that MSS could distinguish the breath of four cancer patients from four healthy people in a double-blind trial.
