Zwitterionic bottlebrush elastomers for bioelectronics

植入式生物电子学的进展正在改变我们对神经疾病的理解和治疗。例如，像Neuralink和Kernel这样的商业企业正在利用光纤般的柔性探头实现超高带宽的脑机接口。由于慢性植入对于终生疾病是必要的，因此重要的是考虑减轻导致装置故障的免疫反应的策略。改善组织相容性的一种方法是通过使用低弯曲刚度结构或低模数材料来降低装置的机械刚性，但这些努力无法与软生物组织的模数相匹配。想想你的嘴唇对手机里的电子产品的柔软度--你可以直观地分辨出柔软度和延伸性的巨大差异。在制造与生物组织具有良好机械匹配的电子材料方面取得了进展；一种被称为水凝胶的材料就是一种。然而，水凝胶含有大量的水，这使电子性能和器件制造变得复杂(例如，很难将湿层粘合在一起)。此外，通过精确的化学功能，延缓和避免设备故障，在制造有效隐形到我们的免疫系统的材料方面也取得了进展。这些材料无污染或有效地模拟自然环境，避免了导致纤维化包膜形成和设备故障的一连串免疫事件。然而，仅有化学策略是不足以长期植入设备的。目前，一种同时利用机械和化学方法的集成材料平台还不存在，并被认为是延长植入时间的潜在解决方案。这里描述的工作是化学家和物理学家之间的合作努力，以合成无污染的超软材料，并随后表征其机械性能，以设计用于可植入设备的下一代涂层。

Advances in implantable bioelectronics are changing our understanding and treatment of neurological disorders. For example, commercial ventures like Neuralink and Kernel are realizing ultra-high-bandwidth brain-machine interfaces with fiber-like flexible probes. Because chronic implantation is needed for lifelong disorders, it is important to consider strategies to mitigate the immunological responses that lead to device failure. One approach to improving tissue compatibility is to reduce the mechanical rigidity of devices by using low bending stiffness architectures or lower-modulus materials, but these efforts have not matched the moduli of soft biological tissue. Consider the softness of your lips to the electronics in your mobile phones-- you can intuitively discern a large difference in softness and stretchability. There have been advances in making electronic materials with a good mechanical match to biological tissue; one example is a class of material called hydrogels. However, hydrogels contain substantial water, which complicates electronic performance and device fabrication (e.g., it is difficult to adhere wet layers together). Also, there have been advances in making materials that are effectively stealth to our immune system through precise chemical functionalities, delaying and avoiding device failure. These materials are non-fouling or effectively mimic the natural milieu, avoiding the cascade of immunological events that leads to fibrotic capsule formation and device failure. However, chemical strategies alone are insufficient for long-term implantation of devices. Currently, an integrated materials platform that exploits both mechanical and chemical approaches does not exist and poses as a potential solution for extending implantation time. There work described herein is a collaborative effort between a chemist and physicist to synthesize ultrasoft materials that are non-fouling and subsequently characterize their mechanical properties to design the next generation of coatings for implantable devices.