CAREER: Optofluidic Solar Indoor Lighting Towards Sustainable Buildings

根据美国能源情报署（Energy Information Administration）的数据，建筑行业的用电量占美国总用电量的70%以上，占美国总能耗的40%。建筑也占美国温室气体排放量的三分之一以上，这比任何其他经济部门都要多。该项目满足了国家和社会对绿色和可持续建筑的重要需求。本研究探索了一种新的光流体方法，可以充分利用屋顶太阳能，不仅可以主动控制照明功率，还可以利用多余的阳光进行室内农业和光伏发电等其他室内太阳能活动。研究成果将真正为追求节能环保建筑的太阳能解决方案提供新的范例。拟议技术的创新包括紧凑轻便的太阳能照明系统，舒适的持续照明，建筑物的电力减少，高质量的室内环境，以及用于其他太阳能室内活动的多余太阳能。该项目需要跨学科的研究和培训，涉及范围从电气工程和表面科学，一直到光学和能源应用。研究生将从这一跨学科研究中获得第一手经验，并为成为未来的领导者做好准备。通过与SDSU的教育项目合作，还将开展外展活动，目的是促进来自代表性不足群体的K-12和社区大学学生以及女性参与STEM学科的高等教育。该项目的目标是开发一种光流太阳能室内照明（OFSIL）系统，充分利用屋顶太阳能，不仅可以主动控制照明功率，用于建筑物内部照明，还可以用于室内其他太阳能活动，如室内农业和光伏发电。PI最近开发了电润湿驱动的液体棱镜，无需任何机械运动部件即可实现高性能光束转向。在这个项目中，可调液体棱镜的概念被用作一种低成本、轻量化和精确的光束导向手段，以实现智能太阳能室内照明。该项目首先着重于纳米材料和光流体现象的基础研究，以实现高性能的太阳光束转向。其次，对主动照明控制的概念论证和大型照明系统的设计优化进行了三维数值模拟研究。最后，开发了一种阵列形式的光流体太阳能照明系统，以演示捕获外部阳光并通过光纤将其引导到建筑物照明内部的可行性。开发的研究成果利用自然光进行室内照明，大大减少建筑物的用电量，并在舒适的阳光照明下提供健康和富有成效的室内环境，朝着绿色和可持续建筑的方向迈进。本研究开发的技术可以进一步应用于其他地下结构（如地铁、隧道、地下室、掩体等），在这些地下结构中，室内照明可以享受自然光，甚至可以在地下深层结构中种植植物。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

According to the U.S. Energy Information Administration, the building sector accounts for more than 70% of all U.S. electricity use and 40% of total U.S. energy consumption. Buildings are also responsible for over one-third of U.S. greenhouse gas emissions, which is more than any other sector of the economy. This project addresses an important national and societal need for green and sustainable buildings. The research explores a novel optofluidic approach that can make full use of rooftop solar energy not only for interior illumination of buildings with active control of lighting power, but also for other indoor solar activities such as indoor farming and photovoltaic generation using excess sunlight. The research outcomes will truly offer a new paradigm in solar energy solutions in the pursuit of buildings that are energy-efficient and environmentally friendly. The innovations of the proposed technology include compact and lightweight solar lighting systems, constant illumination at a comfortable level, electricity reduction in buildings, a high-quality indoor environment, and excess solar energy for other solar indoor activities. The project requires interdisciplinary research and training on issues ranging from electrical engineering and surface science, all the way to optics and energy applications. Graduate students will gain first-hand experience from this interdisciplinary research and be well prepared to be future leaders. Through the collaborations with SDSU’s educational programs, outreach activities will be also conducted with the goal of promoting participation of K-12 and community college students from underrepresented groups and women in higher education in STEM disciplines. The objective of this project is to develop an optofluidic solar indoor lighting (OFSIL) system that can make full use of rooftop solar energy not only for interior illumination of buildings with active control of lighting power, but for other indoor solar activities such as indoor farming and photovoltaic generation. The PI recently developed electrowetting-driven liquid prisms that enabled high-performance beam steering without any mechanical moving parts. In this project, the concept of the tunable liquid prism is used as a low-cost, lightweight, and precise beam steering mean to realize smart solar indoor lighting. The project firstly focuses on fundamental studies of nanomaterials and optofluidic phenomena to achieve high-performance solar beam steering. Secondly, three-dimensional (3D) numerical simulation studies are implemented for the concept demonstration of active lighting control and design optimization of the large-scale lighting system. Lastly, an arrayed form of optofluidic solar lighting systems is developed to demonstrate the feasibility to capture sunlight outside and guide it to interiors through optical fibers for building’s illumination. The developed research outputs utilize natural sunlight for indoor lighting to significantly reduce electricity use in buildings as well as provide healthy and productive indoor environment under comfortable sunlight illumination as a move towards green and sustainable buildings. The technology developed in this research can be further used for other underground structures (e.g. subways, tunnels, basements, shelters, etc.) where natural sunlight can be enjoyed for indoor lighting and even make possible the cultivation of plants in deep underground structures.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.