28 February, 2022
Professor Gilles Lubineau will give a talk in the RobotKAUST.
Location Building 19, Level 3
Advanced composite materials are a key enabling technology for new solutions in energy production, transportation and storage. It is critical to develop monitoring techniques that are viable for a large scale/distributed sensing, which can inform us about the critical condition of the structures, localize and identify their degradation mechanism.
Capacitive sensors are usually preferred for local strain sensing. Yet, the sensitivity of such sensors is guided only by the geometrical change, with a gauge factor close to one. Achieving high sensitivity appeared quite challenging and with limited success so far.
We present here a new concept where high piezoresistive electrodes are used to drastically improved the gauge factor of capacitive sensors.
First, we present our initial work on super high gauge factor in piezoresistive sensing, using fragmented conductive films. This works allows to build electrode with large change in resistance under stretch, that is an enabling component of our capacitive technology.
Second, we present our capacitive technology, the starting point of which is a classical parallel capacitor equipped with highly resistive electrodes. In such a case, the system behaves as a transmission line, resulting in a limited penetration of the interrogation signal over the sensor length. The innovation here is to make this high resistive strain-dependent by introducing well-chosen and designed patterns of cracks inside the electrodes.
This design results in a strain and frequency dependent capacitance, that unlock the potential of capacitive sensing.
Please find the below link for more information: