EAGER: Collaborative Research: Fully water-soluble bioelectronics with skin-conforming galactomannan

这一迫切的项目旨在通过在水溶性超光滑的半乳甘露聚糖基质上制作全水溶锌传感器来实现可生物降解的表皮装置。半乳甘露聚糖是通过环境友好的水提取方法从种子中获得的。虽然人们越来越关注于探索用于植入式监护仪和一次性表皮传感器的生物兼容和可生物降解材料，但这些衬底往往与生物降解性差、表面粗糙度高、缺乏整合性和昂贵的化学合成方法有关。在这个项目中，将在天然来源的半乳甘露聚糖基质上制造、表征和基准测试各种锌传感器。由此产生的一次性电子产品可以被编程为溶于水，并进一步产生环境友好的最终产品，可用于碱性土壤改良剂。考虑到水溶性半乳甘露聚糖对人类健康的诸多好处，如降低血糖和低密度脂蛋白胆固醇水平，这项研究的结果也将使生物医学植入物的未来发展成为可能。此外，这项研究将与一个全面的教育项目紧密结合在一起，该项目将通过早期参与和关于完全水溶性传感器的设计和制造的研究培训，使本科生和代表性不足的学生接触到跨学科技术。在降低表皮装置的弯曲硬度、改善装置-皮肤界面处的接触质量以及产生高质量的传感数据方面已经投入了大量的努力。由于器件的弯曲刚度主要受各器件层的模数和厚度的影响，因此成功的示范包括使用低模数衬底或探索薄型器件结构。然而，前者的材料有限，而后者的低成本制造具有挑战性。此外，这两个类别的非水溶性特性都会产生电子废物流，造成环境问题。提出了一种创新的、完全水溶性的生物电子器件，其中锌传感器通过低成本的制造工艺被制造在半乳甘露聚糖衬底上。本项目的目标是开展一项可行性研究，即在皮肤贴合的半乳甘露聚糖膜上的水溶性生物电子可以与层次化纹理的皮肤表面形成共形接触，并降低接触阻抗。为了完成可行性研究，提出了两项研究任务：(1)在皮肤贴合的半乳甘露聚糖薄膜上制备电容式锌电极和温度传感器；(2)表征水溶性锌传感器的性能，特别是针对运动伪影的性能。通过在没有机械故障的情况下跟踪任意皮肤变形，这种完全一次性、高性能和低成本的新型电子设备可以显著改善设备-皮肤界面的接触质量，并降低对运动伪影的敏感性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This EAGER project aims to realize the biodegradable epidermal devices by fabricating fully water-soluble zinc sensors on a water-soluble and ultra-smooth galactomannan substrate that is obtained from seeds with an environmentally-friendly aqueous extraction method. While there has been increasing attention to exploring biocompatible and biodegradable materials for implantable monitors and disposable epidermal sensors, the substrates are often associated with poor biodegradability, high surface roughness, lack of conformability, and expensive chemical synthesis approaches. In this project, various zinc sensors on the nature-derived galactomannan substrate will be fabricated, characterized, and benchmarked. The resulting disposable electronics can be programmed to dissolve in water, and further produce environmentally benign end-products, which can be used for alkaline soil amendments. Considering the numerous human health benefits such as reducing blood glucose and low-density lipoprotein cholesterol levels of the water-soluble galactomannan, the results from this study will also enable the future development of biomedical implants. Additionally, the research will be tightly coupled with a comprehensive educational program that will expose undergraduate and underrepresented students to interdisciplinary technologies through early engagement and research training on the design and fabrication of fully water-soluble sensors. Significant efforts have been devoted to reducing the bending stiffness of epidermal devices to improve the contact quality at the device-skin interface and to yield high-quality sensing data. As the bending stiffness of the device is primarily affected by the modulus and thickness of each device layer, successful demonstrations include the use of low-modulus substrate or exploration of thin device structures. However, the materials are limited in the former, and low-cost fabrication is challenging in the latter. Additionally, non-water-soluble properties of both classes create electronic waste streams, posing environmental concerns. An innovative, fully water-soluble bioelectronic device is proposed in which zinc sensors are fabricated on the galactomannan substrate through a low-cost fabrication process. The objective of this project is to carry out a feasibility study that water-soluble bioelectronics on a skin-conforming galactomannan film can form a conformal contact with the hierarchically textured skin surface and reduce the contact impedance. Two research tasks are proposed to accomplish the feasibility study: (1) fabricating capacitive zinc electrodes and temperature sensors on the skin-conforming galactomannan films, and (2) characterizing water-soluble zinc sensors to benchmark their performance, particularly against motion artifacts. By following arbitrary skin deformations without mechanical failure, the new class of fully disposable, high-performance, and low-cost electronic devices can significantly improve the contact quality at the device-skin interface and reduce the susceptibility to motion artifacts.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.