School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0245, USA.
School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0250, USA.
Sci Rep. 2016 Dec 23;6:39909. doi: 10.1038/srep39909.
A bio-enabled, environmentally-friendly, and maximally mild layer-by-layer approach has been developed to surface modify inherently hydrophobic Kapton HN substrates to allow for great printability of both water- and organic solvent-based inks thus facilitating the full-inkjet-printing of flexible electronic devices. Different from the traditional Kapton surface modification approaches which are structure-compromising and use harsh conditions to target, and oxidize and/or remove part of, the surface polyimide of Kapton, the present Kapton surface modification approach targeted the surface electric charges borne by its additive particles, and was not only the first to utilize environmentally-friendly clinical biomolecules to build up a thin film of protamine-heparin complex on Kapton, but also the first to be conducted under minimally destructive and maximally mild conditions. Besides, for electrically charged ink particles, the present surface modification method can enhance the uniformity of the inkjet-printed films by reducing the "coffee ring effect". As a proof-of-concept demonstration, reduced graphene oxide-based gas sensors, which were flexible, ultra-lightweight, and miniature-sized, were fully-inkjet-printed on surface modified Kapton HN films and tested for their sensitivity to dimethyl methylphosphonate (a nerve agent simulant). Such fabricated sensors survived a Scotch-tape peel test and were found insensitive to repeated bending to a small 0.5 cm radius.
一种生物增强型、环境友好型且最大限度温和的层层方法已经被开发出来，用于对原本疏水的 Kapton HN 基底进行表面修饰，以实现水基和有机溶剂基墨水的出色打印性能，从而促进柔性电子器件的全喷墨打印。与传统的 Kapton 表面改性方法不同，后者会破坏结构，并使用苛刻的条件来靶向、氧化和/或去除 Kapton 表面聚酰亚胺的一部分，本 Kapton 表面改性方法针对的是其添加剂颗粒所承载的表面电荷，不仅是第一个利用环保的临床生物分子在 Kapton 上构建鱼精蛋白-肝素复合物薄膜，而且也是第一个在最小破坏性和最大限度温和条件下进行的。此外，对于带电的油墨颗粒，本表面改性方法可以通过减少“咖啡环效应”来提高喷墨打印薄膜的均匀性。作为概念验证演示，基于还原氧化石墨烯的气体传感器具有柔韧性、超轻量和微型化的特点，已完全喷墨打印在经过表面修饰的 Kapton HN 薄膜上，并对其对二甲氧基甲基膦酸酯（神经毒剂模拟物）的敏感性进行了测试。这种制造的传感器通过了 Scotch 胶带剥离测试，并且被发现对反复弯曲到小的 0.5cm 半径不敏感。
