A Microscale Power Generator Driven by Tethered Bacterial Flagellar Motors

微米和纳米技术的进步使紧凑型电子设备得以快速发展，用于广泛的商业和军事应用。然而，尽管手机或笔记本电脑等电子设备中的几乎每个组件都变得越来越小，但用于为它们供电的电池仍然相对较大，功率密度较低。目前正在开发几种替代发电机，包括直接甲醇燃料电池、微型内燃机和生物太阳能电池，试图克服电池技术的限制。虽然取得了不同程度的成功，但这三种设计都需要在一些技术领域进行重大改进，才能超越现有的电池。本项目将开发一种新的微型发电机，旨在满足功率密度和系统规模的要求。它也是环保的，没有有害的副产品。从本质上讲，拟议中的发电机是一台微型发电机，只不过它是由旋转的生物细胞驱动的，而不是旋转的磁铁。该项目将利用新的生物和工程技术来创建一种混合系统，将生物细胞中高效分子马达的旋转功率转换为电能。由于拟议工作的前瞻性，该项目预计将产生丰富的新知识，这些知识将影响未来电子设备的设计，并显著增强我们对分子马达的基本理解。该项目将通过包括微生物学和纳米技术在内的多学科领域的交叉培训，为本科生和研究生提供重要的教育机会。这些经验将为他们提供坚实的基础，以面对未来日益需要多学科技能的就业市场。拟议的生物发电机将在微流控系统中集成细菌鞭毛电机、铁磁珠和微/纳米线圈。鞭毛马达是一种具有大扭矩和高功率输出的纳米级分子马达。当马达通过缩短的鞭毛细丝拴在底物上时，它会以10赫兹的稳定转速转动细菌细胞体，提供自然的旋转动力来源。微流控系统中鞭毛电机的操纵和连接将通过光诱导介电泳法(ODEP)来完成。拟议的项目将制造一个微型杂交系统，将ODEP芯片与一种非致病性的基因工程菌株的鞭毛马达结合起来。根据初步的数值模拟结果，鞭毛电机发电机的功率密度与其他基于生物的微型发电机相似。鞭毛电机发电机的制造将基于PIS研究小组在过去十年开发的核心鞭毛电机组装技术。该项目的具体目标包括开发有效的细胞系留协议，开发有效的珠子附着策略，设计和制造ODEP芯片，应用ODEP芯片捕获并实现自由游泳细胞的局部拴系，最后对鞭毛电机发电机进行彻底的性能测试。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。

The advancement of micro- and nanotechnology has enabled the rapid development of compact electronic devices for a wide range of commercial and military applications. However, even though almost every component in an electronic device such as a cell phone or laptop is getting smaller, the batteries used to power them are still relatively large with a low power density. Several alternative power generators including the direct methanol fuel cells, the micro internal combustion engines, and the biological solar cells are currently being developed in an attempt to overcome the constraints of the battery technology. While achieving different degrees of success, all three designs still require significant improvement in a number of technical areas in order to outperform the existing batteries. The present project will develop a new microscale power generator that is designed to meet the demand of both power density and system size. It is also environmentally friendly with no harmful byproducts. Essentially, the proposed power generator is a microscale dynamo except it is driven by rotating biological cells instead of rotating magnets. The project will utilize novel biological and engineering techniques to create a hybrid system that converts the rotational power of the highly efficient molecular motors in the biological cells into electrical power. Due to the forward-looking nature of the proposed works, the project is expected to generate a wealth of new knowledges that will impact the design of future electronic devices and also significantly enhance our fundamental understanding of the molecular motors. The project will provide significant educational opportunities for students at both the undergraduate and graduate levels through cross-training in multidisciplinary areas including microbiology and nanotechnology. Such experience will provide them with a solid foundation to face the future job market that increasingly requires multidisciplinary skills.The proposed biological dynamo will integrate bacterial flagellar motors with ferromagnetic beads and micro/nano coils in a microfluidic system. Flagellar motor is a nanoscale molecular motor capable of a large rotary torque and highpower output. When the motor is tethered to a substrate through a shortened flagellar filament, it turns the bacterial cell body at a stable rotational rate of 10 Hz, providing a natural source of rotational power. Manipulation and tethering of the flagellar motors in the microfluidic system will be accomplished by optically induced dielectrophoresis (ODEP). The proposed project will fabricate a microscale hybrid system that combines an ODEP chip with the flagellar motors of a non-pathogenic, genetically engineered strain of Escherichia coli. Based on the result of a preliminary numerical simulation, the power density of the flagellar motor dynamo is similar to that of other biological based microscale power generators. Fabrication of the flagellar motor dynamo will be based on the core flagellar motor assembly technologies developed by the PIs' research groups over the last decade. Specific objectives of the project include the development of an effective cell tethering protocol, the development of an effective bead attachment strategy, the design and fabrication of an ODEP chip, the application of the ODEP chip to capture and enable local tethering of free swimming cells, and finally a thorough performance testing of the flagellar motor dynamo.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.