@article{SaleemDowneyLaflammeetal.2015,
  author    = {Saleem, Hussam and Downey, Austin and Laflamme, Simon and Kollosche, Matthias and Ubertini, Filippo},
  title     = {Investigation of Dynamic Properties of a Novel Capacitive-based Sensing Skin for Nondestructive Testing},
  series = {Materials evaluation},
  volume    = {73},
  journal   = {Materials evaluation},
  number    = {10},
  publisher = {American Society for Nondestructive Testing},
  address   = {Columbus},
  issn      = {0025-5327},
  pages     = {1390 -- 1397},
  year      = {2015},
  abstract  = {A capacitive-based soft elastomeric strain sensor was recently developed by the authors for structural health monitoring applications. Arranged in a network configuration, the sensor becomes a sensing skin, where local deformations can be monitored over a global area. The sensor transduces a change in geometry into a measurable change in capacitance, which can be converted into strain using a previously developed electromechanical model. Prior studies have demonstrated limitations of this electromechanical model for dynamic excitations beyond 15 Hz, because of a loss in linearity in the sensor's response. In this paper, the dynamic behavior beyond 15 Hz is further studied, and a new version of the electromechanical model is proposed to accommodate dynamic strain measurements up to 40 Hz. This behavior is characterized by subjecting the sensor to a frequency sweep and identifying possible sources of nonlinearities beyond 15 Hz. Results show possible frequency dependence of the materials' Poisson's ratios, which are successfully modeled and integrated into the electromechanical model. This demonstrates that the proposed sensor can be used for monitoring and evaluation of structural responses up to 40 Hz, a range covering the vast majority of the dominating frequency responses of civil infrastructures.},
  language  = {en}
}
@article{LaflammeKolloscheConnoretal.2012,
  author    = {Laflamme, S. and Kollosche, Matthias and Connor, Jerome J. and Kofod, Guggi},
  title     = {Soft capacitive sensor for structural health monitoring of large-scale systems},
  series = {Structural control \& health monitorin},
  volume    = {19},
  journal   = {Structural control \& health monitorin},
  number    = {1},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1545-2263},
  doi       = {10.1002/stc.426},
  pages     = {70 -- 81},
  year      = {2012},
  abstract  = {Structural integrity of infrastructures can be preserved if damage is diagnosed, localized, and repaired in time. During the past decade, there has been a considerable effort to automate the process of structural health monitoring, which is complicated by the inherent large size of civil structures. Hence, a need has arisen to develop new approaches that enable more effective health monitoring. In this paper, a new sensing technique for damage localization on large civil structures is proposed. Specifically, changes in strain are detected using a capacitance sensor built with a soft, stretchable dielectric polymer with attached stretchable metal film electrodes. A change in strain causes a measurable change in the capacitance of the sensor, which can be directly monitored when the sensor is fixed to a structure. The proposed method is shown here to permit an accurate detection of cracks. The proposed system deploys a layer of dielectric polymer on the surface of a structural element, and regularly monitors any change in capacitance, giving in turn information about the structural state. The smart material is composed of inexpensive silicone elastomers, which make the monitoring system a promising application for large surfaces. Results from tests conducted on small- scale specimens showed that the technology is capable of detecting cracks, and tests conducted on large- size specimens demonstrated that several sensor patches organized on a sensor sheet are capable of localizing a crack. The sensor strain also exhibits a high correlation with the loss of stiffness.},
  language  = {en}
}