Piezoresistive sensor matrix for adaptive structures

Abstract

Due to the scarcity of raw materials and the anthropogenic climate change, the importance of adaptive load-bearing structures increases. Adaptability in structural engineering refers to adjusting the behavior and functionality of structural components with respect to changing conditions, such as varying loads. Corresponding optimization processes can be actively controlled by adaptive systems, whereby main components comprise actuators for manipulating the structural behavior and sensors for regulating the actuators. To date, such sensor measurements are mostly carried out locally. However, in adaption processes caused by time-varying loads, local measurements may lead to inaccuracies due to individual load phenomena, such as wind turbulences or snow accumulations in specific parts of structures. Limited attention has been paid on developing holistic, global monitoring systems for detecting and quantifying loads since a multitude of sensors is cost intensive, and the integration into the building envelope challenging. Based on previous work, this paper investigates slender piezoresistive pressure sensor matrices to quantify wind and snow loads. After a brief introduction into adaptive structures, a framework for large-scale monitoring systems based on sensor matrices is proposed. Subsequently, working principles and low-cost fabrication of piezoresistive sensor matrices are presented. Finally, the sensors are validated and applications as well as future work for practical implementation are discussed. In summary, the low-cost pressure sensor matrices appear promising to globally quantify and localize actions on structures and may offer a wide application range for adaptive structures.