A platform material for melt electrowriting : shape memory poly(alkylene terephthalate)s with tunable thermo-mechanical properties

Melt electrowriting (MEW) is a state-of-the-art additive manufacturing technique, often used in tissue engineering, that enables the high-resolution production of constructs composed of accurately positioned and stacked microscale fibers. One major limitation is the small pool of processable polymers, limiting the obtainable material properties and therefore the ability to match the requirements of certain applications. In this work, poly(alkylene terephthalate)s (PATs) are introduced to the MEW field, and their potential is demonstrated. PATs are biocompatible and have adjustable material properties depending on their alkyl chain length, making them highly versatile and tunable. PATs with alkyl chain lengths of 5 to 12 are synthesized and characterized chemically, thermally, and mechanically. Melting points ranging from 98°C to 150°C and Young's moduli between 117.2 and 574.7 MPa are obtained, highlighting their diversity in material properties. All tested PATs are processable using the same parameters, only varying the applied voltage difference. Further optimization using PAT with an alkyl chain length of 7 enables fabrication of constructs with various architectures, which exhibit excellent shape memory behavior. With their broad range of thermal and mechanical properties and minimal process optimization requirements, PATs offer a promising material platform for a plethora of applications.