Liquid detection sensor

A liquid detection sensor, comprising a metal-air battery having:

• a positive electrode,
• a negative electrode,
• a support member having voids and supporting the positive electrode and the negative electrode, wherein the support member is arranged between the positive electrode and the negative electrode,
• a plurality of resin-made bags, wherein each resin-made bag is introduced into an associated void of the support member, and a resin of each resin-made bag has dissolvability or dispersibility in a liquid being an object to be detected, and
• a plurality of electrolytic solution-forming components, wherein each electrolytic solution-forming component is enclosed in the inside of an associated resin-made bag of the plurality of resin-made bags,
• wherein each resin-made bag comprises:
• an oil-soluble resin, or
• a water-soluble resin composite comprising a polyvinyl alcohol-based polymer with at least one resin selected from a group of resins consisting of a polysaccharide and an acrylic resin.