RVmagnetics MicroWire sensors are essentially metallic alloys with glass coating. Coating here refers to the surrounding of the sensor with glass as thin as 2–20 µm in diameter. The glass (and sensor as such) is flexible like human hair and doesn’t break easily when bended.
in RVmagnetics' case, glass coating material is similar to borosilicate glass (commonly used as material for petri dishes). This makes the sensor biocompatible, and resistant to chemically aggresive environments .