The smallest movements in building or bridge materials can cause big problems.
 
A researcher at Missouri University of Science and Technology has been awarded a patent for a sensor he says can track if composite building materials have even the tiniest of movements and help prevent structures from collapsing or having less integrity.  
 
“The most common example of composite materials in construction is beams made from both steel and concrete, but the main idea is to have two different materials bonded together to enhance the strength of a structure,” says Dr. Genda Chen, S&T’s Robert W. Abbett Distinguished Chair in Civil Engineering and director of the Center for Intelligent Infrastructure and the INSPIRE University Transportation Center.
 
 “These materials should have zero movement. If they separate for whatever reason, this can lead to some significant problems with the structure and its safety.”
 
 To monitor movements that could be as small as one micrometer — or one-thousandth of a millimeter — Chen has patented a device that uses a mirror connected to a fiber-optic cable about as thick as a human hair follicle.
 
 This sensor can be connected directly onto a structure’s steel and concrete composites and is designed so that the mirror, which has a microscopic pattern on it, can use light and reflections in multiple ways to measure any displacement, or change in positions, between the materials.
 
 “What is exciting is this technology can be a non-destructive testing method when the sensor is installed during construction, and there is a serious need for this,” Chen says. “Movements will be detected much sooner, and then engineers can work to re-bond the materials.”
 
 Chen says the sensor is likely still several years away from being commercialized and available on a large scale, but he is excited to be awarded the patent and begin taking the next steps toward it eventually being used by structural engineers.
  
 “Working to develop technology that is so directly applicable to real life is dear to my heart,” he says. “As I have advanced in my career over the past three decades, my research has increasingly focused on concepts that could more quickly make a tangible, real difference for society.”
 
 Other inventors on the patent with Chen include Drs. Jie Gao, a former S&T faculty member, and Chuanrui Guo, an S&T alumnus who earned a Ph.D. in civil engineering under Chen’s supervision.
 
For more information about S&T’s civil engineering programs, visit care.mst.edu.