@article{WangRychkovGerhard2017, author = {Wang, Jingwen and Rychkov, Dmitry and Gerhard, Reimund}, title = {Chemical modification with orthophosphoric acid enhances surface-charge stability on polypropylene electrets}, series = {Applied physics letters}, volume = {110}, journal = {Applied physics letters}, publisher = {American Institute of Physics}, address = {Melville}, issn = {0003-6951}, doi = {10.1063/1.4983348}, pages = {5}, year = {2017}, abstract = {The low surface-charge stability of polypropylene (PP) frequently limits its application as an electret material. In this paper, we demonstrate how the treatment of PP-film surfaces with orthophosphoric acid (H3PO4) enhances their charge stability. To discriminate between the effects of chemical modification and thermal treatment, as-received and annealed PP films are used as reference samples. The electret properties of treated and non-treated PP films are characterized with thermally stimulated discharge (TSD) and isothermal surface-potential decay (ISPD) experiments, from which considerable improvement in thermal and temporal charge stability is observed for samples modified with H3PO4. The half-value temperature (T-1/2) observed on TSD curves of chemically treated PP increases to 131 and 145 degrees C for positive and negative charges, respectively. The enhancement might be attributed to the phosphoric compounds detected on the H3PO4-modified surfaces via attenuated-total-reflection infrared spectroscopy. Deeper surface traps formed at the "foreign" phosphorus-containing structures are able to capture the charges over longer time periods and at higher temperatures, thus leading to significant improvements in the temporal and thermal surface-charge stabilities of PP electrets. Published by AIP Publishing.}, language = {en} } @misc{LouposDamigosAmditisetal.2017, author = {Loupos, Konstantinos and Damigos, Yannis and Amditis, Angelos and Gerhard, Reimund and Rychkov, Dmitry and Wirges, Werner and Schulze, Manuel and Lenas, Sotiris-Angelos and Chatziandreoglou, Christos and Malliou, Christina and Tsaoussidis, Vassilis and Brady, Ken and Frankenstein, Bernd}, title = {Structural health monitoring system for bridges based on skin-like sensor}, series = {IOP conference series : Materials science and engineering}, volume = {236}, journal = {IOP conference series : Materials science and engineering}, publisher = {IOP Publ. Ltd.}, address = {Bristol}, issn = {1757-8981}, doi = {10.1088/1757-899X/236/1/012100}, pages = {10}, year = {2017}, abstract = {Structural health monitoring activities are of primal importance for managing transport infrastructure, however most SHM methodologies are based on point-based sensors that have limitations in terms of their spatial positioning requirements, cost of development and measurement range. This paper describes the progress on the SENSKIN EC project whose objective is to develop a dielectric-elastomer and micro-electronics-based sensor, formed from a large highly extensible capacitance sensing membrane supported by advanced microelectronic circuitry, for monitoring transport infrastructure bridges. Such a sensor could provide spatial measurements of strain in excess of 10\%. The actual sensor along with the data acquisition module, the communication module and power electronics are all integrated into a compact unit, the SENSKIN device, which is energy-efficient, requires simple signal processing and it is easy to install over various surface types. In terms of communication, SENSKIN devices interact with each other to form the SENSKIN system; a fully distributed and autonomous wireless sensor network that is able to self-monitor. SENSKIN system utilizes Delay-/Disruption-Tolerant Networking technologies to ensure that the strain measurements will be received by the base station even under extreme conditions where normal communications are disrupted. This paper describes the architecture of the SENSKIN system and the development and testing of the first SENSKIN prototype sensor, the data acquisition system, and the communication system.}, language = {en} }