TY  - JOUR
A1  - Laflamme, Simon
A1  - Kollosche, Matthias
A1  - Connor, Jerome J.
A1  - Kofod, Guggi
T1  - Robust flexible capacitive surface sensor for structural health monitoring applications
JF  - Journal of engineering mechanics
N2  - Early detection of possible defects in civil infrastructure is vital to ensuring timely maintenance and extending structure life expectancy. The authors recently proposed a novel method for structural health monitoring based on soft capacitors. The sensor consisted of an off-the-shelf flexible capacitor that could be easily deployed over large surfaces, the main advantages being cost-effectiveness, easy installation, and allowing simple signal processing. In this paper, a capacitive sensor with tailored mechanical and electrical properties is presented, resulting in greatly improved robustness while retaining measurement sensitivity. The sensor is fabricated from a thermoplastic elastomer mixed with titanium dioxide and sandwiched between conductive composite electrodes. Experimental verifications conducted on wood and concrete specimens demonstrate the improved robustness, as well as the ability of the sensing method to diagnose and locate strain.
KW  - Strain gages
KW  - Structural health monitoring
KW  - Monitoring
KW  - Probe instruments
KW  - Strain gauge
KW  - Structural health monitoring
KW  - Strain monitoring
KW  - Capacitive sensor
KW  - Dielectric polymer
KW  - Stretchable sensor
KW  - Flexible membrane
KW  - Sensing skin
Y1  - 2013
U6  - https://doi.org/10.1061/(ASCE)EM.1943-7889.0000530
SN  - 0733-9399
SN  - 1943-7889
VL  - 139
IS  - 7
SP  - 879
EP  - 885
PB  - American Society of Civil Engineers
CY  - Reston
ER  - 
TY  - JOUR
A1  - Poghossian, A.
A1  - Weil, M.
A1  - Cherstvy, Andrey G.
A1  - Schöning, M. J.
T1  - Electrical monitoring of polyelectrolyte multilayer formation by means of capacitive field-effect devices
JF  - Analytical & bioanalytical chemistry
N2  - The semiconductor field-effect platform represents a powerful tool for detecting the adsorption and binding of charged macromolecules with direct electrical readout. In this work, a capacitive electrolyte-insulator-semiconductor (EIS) field-effect sensor consisting of an Al-p-Si-SiO2 structure has been applied for real-time in situ electrical monitoring of the layer-by-layer formation of polyelectrolyte (PE) multilayers (PEM). The PEMs were deposited directly onto the SiO2 surface without any precursor layer or drying procedures. Anionic poly(sodium 4-styrene sulfonate) and cationic weak polyelectrolyte poly(allylamine hydrochloride) have been chosen as a model system. The effect of the ionic strength of the solution, polyelectrolyte concentration, number and polarity of the PE layers on the characteristics of the PEM-modified EIS sensors have been studied by means of capacitance-voltage and constant-capacitance methods. In addition, the thickness, surface morphology, roughness and wettabilityof the PE mono- and multilayers have been characterised by ellipsometry, atomic force microscopy and water contact-angle methods, respectively. To explain potential oscillations on the gate surface and signal behaviour of the capacitive field-effect EIS sensor modified with a PEM, a simplified electrostatic model that takes into account the reduced electrostatic screening of PE charges by mobile ions within the PEM has been proposed and discussed.
KW  - Field-effect
KW  - Capacitive sensor
KW  - Polyelectrolyte multilayer
KW  - Electrical monitoring
KW  - ConCap
Y1  - 2013
U6  - https://doi.org/10.1007/s00216-013-6951-9
SN  - 1618-2642
VL  - 405
IS  - 20
SP  - 6425
EP  - 6436
PB  - Springer
CY  - Heidelberg
ER  -