Flexible and Biodegradable Collagen-Based Organic Field-Effect Transistors

Each year, around 50 million tons of consumer electronic products are discarded worldwide ¹. This e-waste is the fastest-growing solid waste stream in the world. Since e-waste is a global environmental challenge, an emerging opportunity to address this problem is to develop biodegradable electronic devices, employing eco-friendly solvents, and recyclable materials and using, preferably, bio-sourced materials. Organic field-effect transistors (OFETs) are a promising type of organic electronics, particularly with the increasing need for new wearable, flexible, stretchable, and implantable technologies. Despite numerous important developments towards the completion of all of the above aims, designing and developing an intrinsically stretchable and biodegradable transistor from environmentally sustainable sources remains an important challenge.<br/>To tackle this, our work focuses on the design of flexible OFETs from selected biomaterials and finds new strategies to balance key device characteristics, including electronic properties, degradation kinetics, and mechanical compliance. Finding this balance will ultimately result in devices with enhanced compatibility with biological tissues for new applications and will contribute to reducing the bioaccumulation of used electronics. While numerous reports have focused on key biomaterials, both natural and synthetic for the development of OFETs, such as silk, poly (lactic-<i>co</i>-glycolic acid), and cellulose, limited attention has been given collagen, and poly(glycerol sebacate). Notably, these two polymers can be as dielectrics and substrates respectively, opening new opportunities in organic and printed electronics due to their biodegradability and stretchability.<br/>This presentation will highlight the results obtained from a detailed morphological, mechanical, and electrical characterization of OFETs fabricated on poly(glycerol sebacate) using collagen as bio-sourced dielectric materials. The various components of the transistor were characterized through multiple techniques including optical and atomic force microscopy, X-ray scattering, tensile stress tests, and others to unravel new structure-property relationships. This presentation will also discuss the electronic properties of the OFETs upon bending and stretching. Finally, biocompatibility, assessed through <i>in vitro</i> assays, will be discussed.<br/><b>References:</b><br/>F. Torricelli, I. Alessandri, E. Macchia, I. Vassalini, M. Maddaloni and L. Torsi, Green Materials and Technologies for Sustainable Organic Transistors, Adv. Mater. Technol.