Zhou Yu, Feng Bo, Chen Lei, Fan Fu, Ji Zhiqiang, Duan Huigao
College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, PR China.
Greater Bay Area Institute for Innovation, Hunan University, Guangzhou 511300, PR China.
ACS Appl Mater Interfaces. 2024 Mar 20;16(11):13525-13533. doi: 10.1021/acsami.3c18576. Epub 2024 Mar 11.
Flexible electronics have been of great interest in the past few decades for their wide-ranging applications in health monitoring, human-machine interaction, artificial intelligence, and biomedical engineering. Currently, transfer printing is a popular technology for flexible electronics manufacturing. However, typical sacrificial intermediate layer-based transfer printing through chemical reactions results in a series of challenges, such as time consumption and interface incompatibility. In this paper, we have developed a time-saving, wafer-recyclable, eco-friendly, and multiscale transfer printing method by using a stable transferable photoresist. Demonstration of photoresist with various, high-resolution, and multiscale patterns from the donor substrate of silicon wafer to different flexible polymer substrates without any damage is conducted using the as-developed dry transfer printing process. Notably, by utilizing the photoresist patterns as conformal masks and combining them with physical vapor deposition and dry lift-off processes, we have achieved in situ fabrication of metal patterns on flexible substrates. Furthermore, a mechanical experiment has been conducted to demonstrate the mechanism of photoresist transfer printing and dry lift-off processes. Finally, we demonstrated the application of in situ fabricated electrode devices for collecting electromyography and electrocardiogram signals. Compared to commercially available hydrogel electrodes, our electrodes exhibited higher sensitivity, greater stability, and the ability to achieve long-term health monitoring.
在过去几十年中，柔性电子因其在健康监测、人机交互、人工智能和生物医学工程等广泛领域的应用而备受关注。目前，转移印刷是柔性电子制造的一种流行技术。然而，典型的基于牺牲中间层的通过化学反应的转移印刷会带来一系列挑战，如耗时和界面不相容性。在本文中，我们通过使用一种稳定的可转移光刻胶开发了一种省时、晶圆可回收、环保且多尺度的转移印刷方法。利用所开发的干转移印刷工艺，对从硅晶圆供体基板到不同柔性聚合物基板的具有各种高分辨率和多尺度图案的光刻胶进行了无损转移演示。值得注意的是，通过将光刻胶图案用作保形掩膜并将其与物理气相沉积和干法剥离工艺相结合，我们在柔性基板上实现了金属图案的原位制造。此外，还进行了一项力学实验以证明光刻胶转移印刷和干法剥离工艺的机理。最后，我们展示了原位制造的电极装置在采集肌电图和心电图信号方面的应用。与市售水凝胶电极相比，我们的电极表现出更高的灵敏度、更大的稳定性以及实现长期健康监测的能力。
