Babaroud Nasim Bakhshaee, Dekker Ronald, Serdijn Wouter, Giagka Vasiliki
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:3399-3402. doi: 10.1109/EMBC44109.2020.9175646.
Parylene-C has been used as a substrate and encapsulation material for many implantable medical devices. However, to ensure the flexibility required in some applications, minimize tissue reaction, and protect parylene from degradation in vivo an additional outmost layer of polydimethylsiloxane (PDMS) is desired. In such a scenario, the adhesion of PDMS to parylene is of critical importance to prevent early failure caused by delamination in the harsh environment of the human body. Towards this goal, we propose a method based on creating chemical covalent bonds using intermediate ceramic layers as adhesion promoters between PDMS and parylene.To evaluate our concept, we prepared three different sets of samples with PDMS on parylene without and with oxygen plasma treatment (the most commonly employed method to increase adhesion), and samples with our proposed ceramic intermediate layers of silicon carbide (SiC) and silicon dioxide (SiO). The samples were soaked in phosphate-buffered saline (PBS) solution at room temperature and were inspected under an optical microscope. To investigate the adhesion property, cross-cut tape tests and peel tests were performed. The results showed a significant improvement of the adhesion and in-soak long-term performance of our proposed encapsulation stack compared with PDMS on parylene and PDMS on plasma-treated parylene. We aim to use the proposed solution to package bare silicon chips on active implants.
聚对二甲苯-C已被用作许多可植入医疗设备的基底和封装材料。然而，为确保某些应用所需的柔韧性、将组织反应降至最低，并保护聚对二甲苯在体内不发生降解，需要额外添加一层最外层的聚二甲基硅氧烷（PDMS）。在这种情况下，PDMS与聚对二甲苯之间的粘附力对于防止在人体恶劣环境中因分层导致的早期失效至关重要。为实现这一目标，我们提出了一种基于使用中间陶瓷层作为PDMS和聚对二甲苯之间的粘附促进剂来创建化学共价键的方法。为评估我们的概念，我们制备了三组不同的样品：聚对二甲苯上涂覆PDMS且未经氧等离子体处理的样品、聚对二甲苯上涂覆PDMS且经氧等离子体处理的样品（这是最常用的增加粘附力的方法），以及带有我们提出的碳化硅（SiC）和二氧化硅（SiO）陶瓷中间层的样品。将样品在室温下浸泡在磷酸盐缓冲盐水（PBS）溶液中，并在光学显微镜下进行检查。为研究粘附性能，进行了划格胶带试验和剥离试验。结果表明，与聚对二甲苯上的PDMS以及经等离子体处理的聚对二甲苯上的PDMS相比，我们提出的封装堆叠的粘附力和浸泡后的长期性能有显著改善。我们旨在使用所提出的解决方案来封装有源植入物上的裸硅芯片。
