Huang Yu-Chun, Yamamoto Shuto, Chen Jung-Yao, Su Chun-Jen, Jeng U-Ser, Higashihara Tomoya, Lin Yan-Cheng
Department of Chemical Engineering, National Cheng Kung University, Tainan 70101, Taiwan.
Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 990-0021, Japan.
ACS Appl Mater Interfaces. 2025 Apr 9;17(14):21521-21535. doi: 10.1021/acsami.5c00047. Epub 2025 Mar 27.
The rise of flexible electronic devices has led to extensive research into conjugated polymer structural engineering. Integrating polymer channels and contact electrodes, warranting high stretchability, is still critical, and the microcracked gold technique provides a potential strategy to integrate them. Conjugated block copolymers have gained significant attention due to their high flexibility, allowing for tailored polymer structures to meet the specific requirements of different device characteristics. In this study, novel N-type multiblock copolymers (multi-BCPs) composed of rigid poly(naphthalene diimide--bithiophene) and flexible polyisobutylene segments were successfully synthesized as polymer semiconductors for the first time. The materials are named based on the weight fraction of soft segments: NDI (0 wt %), mAB73 (27 wt %), and mAB60 (40 wt %). The study explores the mechanical properties, crystallinity, and electrical performance of flexible multi-BCPs. The results show that introducing soft segments significantly enhances stretchability, with crack-onset strains beyond 100% because of their low elastic moduli of 40-50 MPa. Furthermore, the OFET device of mAB73 achieves unchanged mobility under 100% strain, outperforming mAB60 due to excessive polyisobutylene blocks. At the end of this study, an integrated stretchable device with high stretchability is fulfilled by utilizing the microcracked gold technique to combine the multi-BCP channels and contact electrodes. The integrated device can be applied to biomedical electronics without toxic or corrosive electrode materials. The influencing factors, including contact resistance, channel charge mobility, and electrode resistance, are systematically studied to investigate the integrated device's mobility-stretchability relationship. The results indicate that the contact resistance between the multi-BCP channels and contact electrodes is essential to the device's performance. Among these, mAB73, containing soft segments, exhibits more stability than NDI due to the microcracked gold electrodes with infiltrated gold nanoparticles in the rubbery channel surface. Appropriately incorporating soft segments significantly enhances mobility retention under tensile strains, highlighting the potential of multi-BCP designs in stretchable electronic applications.
柔性电子设备的崛起引发了对共轭聚合物结构工程的广泛研究。将聚合物通道与接触电极集成在一起，并保证高拉伸性，仍然至关重要，而微裂纹金技术提供了一种将它们集成的潜在策略。共轭嵌段共聚物因其高柔韧性而受到广泛关注，这使得定制聚合物结构以满足不同器件特性的特定要求成为可能。在本研究中，首次成功合成了由刚性聚（萘二酰亚胺-联噻吩）和柔性聚异丁烯链段组成的新型N型多嵌段共聚物（多BCP）作为聚合物半导体。这些材料根据软段的重量分数命名：NDI（0 wt%）、mAB73（27 wt%）和mAB60（40 wt%）。该研究探索了柔性多BCP的力学性能、结晶度和电学性能。结果表明，引入软段显著提高了拉伸性，由于其40-50 MPa的低弹性模量，裂纹起始应变超过100%。此外，mAB73的有机场效应晶体管（OFET）器件在100%应变下迁移率保持不变，由于聚异丁烯嵌段过多，其性能优于mAB60。在本研究结束时，通过利用微裂纹金技术将多BCP通道与接触电极相结合，实现了具有高拉伸性的集成可拉伸器件。该集成器件可应用于生物医学电子领域，无需使用有毒或腐蚀性电极材料。系统研究了包括接触电阻、通道电荷迁移率和电极电阻在内的影响因素，以研究集成器件的迁移率-拉伸性关系。结果表明，多BCP通道与接触电极之间的接触电阻对器件性能至关重要。其中，含有软段的mAB73由于在橡胶状通道表面渗透有金纳米颗粒的微裂纹金电极，比NDI表现出更高的稳定性。适当引入软段显著提高了拉伸应变下的迁移率保持率，突出了多BCP设计在可拉伸电子应用中的潜力。
