The fabrication of next generation electronics needs greener materials. Transition from fossil-based materials and energy towards renewable and environmentally friendly materials and technologies is needed. Furthermore, better utilization of side/waste stream materials is important. Studies show that in printed electronics, inks and adhesives have high environmental footprint in many impact categories. However, most materials can be either replaced with a greener alternative, or their consumption can be reduced significantly. In addition, manufacturing is pushing us towards low-cost, energy-efficient electronic components and systems and for using the mass-production techniques, like printing. Increased sustainability can be obtained by optimizing the design, structure and processing for the selected use case specifications, and to balance the designed configuration with the requirements set for the device efficiency and system performance.

Objectives for increasing the environmental sustainability are based on renewable, abundant and non-hazardous materials, energy- and material-efficient processing, and end-of-life strategies. An understanding in substrate handling is important when commonly used printed electronics’ substrates are replaced with biobased substrates, as different material properties and their durability define the processing conditions, and stability. On the other hand, some biobased substrates can improve printed electronics performance when compared with the fossil-based substrates. In many applications, silver can be replaced with other metals and carbon, which also increases economic viability. Among printed devices, organic photovoltaics (OPV) can be fabricated with low environmental impact materials and utilized in indoor-light applications without compromising the device efficiency. Pilot-printed, indoor-light optimized OPV modules have reached power conversion efficiencies of over 13%. Harvested energy is sufficient for providing 24-hour energy autonomy in low-power systems, and compatible for sustainable energy harvesting and storage concepts. As a result, flexible low-power sensing systems can be fabricated from greener materials using energy efficient processing at ambient conditions for various application areas, including smart tags and labels.

Marja Välimäki received her M.Sc. degree in Process Engineering, and she is working as senior scientist in Printed Materials Systems team at VTT Technical Research Centre of Finland Ltd. Her research work has focused on the fabrication of optoelectronic devices such as organic-based photovoltaics, with an emphasis on process up-scaling, and the implementation of environmentally sustainable materials and processes to promote sustainability in printed and hybrid electronics.