Self-powered flexible oxygen sensors for intelligent food packaging

A self-powered flexible oxygen gas sensor has been developed for intelligent food packaging, which provides users with information on quality and safety of packaged food during storage and transport. Unlike most conventional oxygen sensors for intelligent packaging, this sensor based on an electrochemical battery requires no external power sources for oxygen sensing. The self-powered flexible oxygen sensor was composed of three layers: a silver-deposited oriented polypropylene film (cathode), a zinc sheet (anode), and an adhesive gel electrolyte. This film-type sensor was flexible, robust, and lightweight. This self-powered sensor generated the output voltage, which was linearly proportional to the oxygen gas concentration in the range of 0-21% (R-2 = 0.999) with a sensitivity of 18 mV/% O-2 and a good repeatability. The oxygen gas concentrations measured with this sensor were in good agreement with those with an expensive oxygen gas analyzer. Due to its good features and performance, it is expected that the self-powered flexible oxygen sensor will be commercially applied to intelligent food packaging for healthier and safer foods.