Printed electronics based on inorganic conductive nanomaterials and their applications in intelligent food packaging

The diverse demands of consumers for packaging functions and increasingly complex product circulation systems have spurred the development of intelligent food packaging (IFP). Besides the basic functions of traditional food packaging, which include the protection of food, sales promotion and convenient transportation, the developing area of IFP can detect the condition of food (ambient temperature, humidity, corruption degree, etc.) in one whole product cycle, and record and feedback information regarding the quality of the packaged food to form a complete product monitoring system. Recently, cutting-edge printed electronics (PE) technology has opened new opportunities for the realization and expansion of IFP functions. Here we introduce some new printed sensors and radio frequency identification (RFID) tags, which are used to form an IFP system. Since conductive ink is the cornerstone of PE, in this paper, the synthesis and properties of inorganic conductive nanomaterials are also reviewed. The formulation of conductive ink, sintering methods and the flexible substrates used in PE are also discussed. Focusing on the state-of-the-art application of PE in the field of IFP, the purpose of this article is to provide a review of IFP that integrates emerging PE technology with prospective next-generation IFP systems to sense, detect, and record feedback information on products in the supply chain environment.