All-printed flexible heaters based on dendritic Ag inks for heatable packaging applications

Abstract

Self-heating packaging has broad application prospects in the fields of food, medical and outdoor use, but traditional chemical heating methods have problems such as uneven heating, low thermal efficiencies, high rigidity and insufficient safety. Herein, a flexible heater based on highly conductive dendritic silver (Ag FDs) was prepared by screen printing to achieve a low-cost and scalable self-heating packaging solution. The results show that the flexible printed heater (FPH) exhibits excellent thermal stability on paper and PET substrates, reaching 54.83 °C and 95.26 °C respectively at a voltage of 3 V, and still maintains good heating performance after being exposed to ambient air for 30 days. The FPH array printed on the four sides of the packaging box can make the internal temperature of the packaging box reach 77.16 °C at a voltage of 5 V, providing a continuous and stable heating environment for the products in the box. The Ag FD-based fully-printed FPHs exhibit excellent heating performances and stabilities, which can meet the needs of heatable packaging for efficient, convenient and safe heating, and provide important support for flexible heating technology in the field of intelligent packaging, and they have broad application prospects.