Wireless sensor networks and flexible electronics as innovative solution for smart greenhouse monitoring in long-term space missions

For long-term space missions the possibility to grow vegetables and fruits inside the spacecraft or in specific living modules is pivotal. The use of indoor greenhouse is a realistic solution. However, the remote monitoring of different control functions of greenhouses remains mandatory. Indeed, this can lead to an increment of the sustainability and can increase product yield. However, a full greenhouse automation needs a continuous monitoring of different key parameters such as humidity, temperature, light intensity, CO2 concentration, etc. Low consumption wireless sensors networks represent a valuable ally to successfully define in real time how the climate inside and outside the greenhouse is changing. Among different solutions, we propose a wireless sensor network based on nodes composed by autonomous flexible patches equipped with sensors, signal processing unit, energy module and data transmission interface. In this work, we adopt both commercial and ad hoc devices such as Layered Double Hydroxides sensors to be used at low working temperature. The resulting devices exploit the porosity of disordered nanostructures and the humidity present in the air to activate the adsorption procedure, thus operating at room temperature. With this technology is possible to monitoring CO2, NOX and other gases present in the greenhouse together with humidity, temperature and light intensity.