As the usage of materials and energy in civil infrastructure surpasses what mother-nature can provide, we need to transform our civil infrastructure system into a new generation with reduced consumption of earth's resources, minimized output of the waste and pollution, extended lifetime, and high energy yield. More than 65% of the energy consumption in the US is attributed to infrastructure components that include residential and commercial buildings, railways and highways. This is seen in the form of heating, cooling, lighting, vehicle powering, material production and construction for these elements. And the durability is most devastatingly affected by solar radiation, temperature, moisture and other environmental conditions that lead to aging and degradation observed in corroded, cracked and spalling surface materials of these infrastructure elements. Energy efficiency as well as durability improvements in the envelopes of these infrastructure components can produce vast improvements of sustainability. Solar energy harvesting through an infrastructure envelope can serve not only to provide self-supplied sustaining clean energy toward net-zero energy infrastructure energy consumption, but additionally, developing such envelopes with reliable performance monitoring system can also offer design opportunities for surface materials that will have improved resistance to deterioration from the environment and thus greater longevity.
As a step toward this goal, the Sustainable Engineering and Materials Laboratory has been established in the Carleton Laboratory of Columbia University. This research group is developing research approaches to characterize, simulate and analyze multi-physical material behavior at macro-, micro-, and nano- scales and participating in interdisciplinary research projects covering mechanics, materials, structures, green technologies, and nondestructive testing. The recent research focuses on discovery, design, and development of advanced materials, structures and systems for energy, environmental, and economic benefits, including multifunctional building envelope for energy efficient buildings, smart sensor materials, low energy asphalt production technologies, and sustainable transportation infrastructure system.
Two types of solar energy harvesting systems have been designed and prototyped: 1) a hybrid solar roofing panel integrating a photovoltaic (PV) layer, and a functionally graded material (FGM) layer with a hot water collector for improved PV efficiency and indoor thermal comfort through an autonomous temperature control, and 2) a concentrated solar thermal system that uses high efficiency evacuated tube collectors (ETC), a passive solar tracker, a phase change material storage unit and a quantum dot (QD) TE generator to collect solar heat, then store and transfer it into electricity. The above two technologies are proposed to be used in residential, commercial, and industrial buildings. Recently, we proposed to use them to form a sun tunnel on our roadway system for self-supplied energy and road material protection. We have investigated energy conversion analysis, heat transfer simulation and modeling, material testing, and manufacturing process. To scale up my hybrid solar roofing panel technology from the laboratory to mass production, we have proposed a sedimentation-based manufacturing method. We mixed aluminum (Al) and high density polyethylene (HDPE) powders in ethanol to automatically create a graded mixture. To understand the particle sedimentation process, a multiple-particle system has been simulated through the equivalent inclusion method (EIM), which was originally proposed by Eshelby for solids but was recently extended to fluids by this group. For the Stokes' flow of one particle (drop) moving in a different fluid, our solution recovers the classic solution. The beauty of our method is that it is applicable to the case of many particles (drops) with different material properties and sizes. Using different fundamental solutions, such as Mindlin's solution among others, we can solve boundary value problems for semiinfinite solids and multilayered materials.
An effective research approach to energy sustainability of civil infrastructure have been being established in five dimensions: increasing energy income, reducing energy consumption, assuring lifecycle performance, improving system efficiency, and extending structure lifetime. The research results have contributed to elastic fundamental solutions, manyparticle systems, multilayered materials, and nanomaterials. It will lead to efficient, durable, affordable, and aesthetically pleasing building envelope and infrastructure surface, with recyclable parts at the end of their useful life, toward the ultimate goal of net zero energy and waste of the infrastructure system.
1. Y.J. Liu, H.M. Yin, Stress concentration of a micro-void embedded in an adhesive layer during stress transfer. Journal of
Engineering Mechanics - ASCE (in press).
2. P.-H. Lee, H.M. Yin, Experimental investigation and numerical simulation of aluminum particle sedimentation toward
functionally graded material fabrication. Journal of Nanomechanics and Micromechanics - ASCE (in press).
3. H.M. Yin, D.J. Yang, G. Kelly, J. Garant, Design and performance of a novel building integrated PV/thermal system for
energy efficiency of buildings, Solar Energy, 87, 184-195, 2013.
4. D.J. Yang, Z.F. Yuan, P.H. Lee, H.M. Yin, Simulation and experimental validation of heat transfer in a novel hybrid solar
panel, International Journal of Heat and Mass Transfer, 55, 1076-1082, 2012.
5. D.J. Yang, H.M. Yin, Energy conversion efficiency of a novel hybrid solar system for photovoltaic, thermoelectric, and heat
utilization, IEEE Transaction of Energy Conversion, 26, 662-670, 2011.