Clevertex - Grado Zero Espace Srl

generated by a light source and is passed through the optical fibre. When the light returns through the
fibre, it is captured by a photo detector [173].
The Canadian company TACTEX Controls, Inc., commercialises a pressure sensing optical fibres
based material capable in detecting pressure on its whole surface, called Kinotex ® derived from
“kinaesthetic textiles”. The sensor systems and components appear like thin sheets of a material
based on urethane or silicone cellular elastomers. Within the material, several pressure sensors,
called taxels, are installed, whose density and performance characteristics are adjusting to the
requirements of the product. Each taxel is consists of a tiny light source and a tiny detector imbedded
in a thin cellular elastomer. As pressure is applied to the elastomer in the region of the taxel, the cell
size distribution is altered along with the bulk optical scattering properties of the material in that area.
The light detector measures the change in scattered light intensity at the taxel, and interprets this as a
change in pressure. Optical fibres laminated into the structure are used as the “nervous system”, to
deliver transmitted light to the location of the taxels, and to deliver received light back from the taxel. In
Tactex products, the light source is typically a light emitting diode (LED) connected to a bundle of
fibres, and the light detector is usually a photodiode or an array of detectors connected to a second
set of fibres. A microcontroller or DSP is used that converts the signals from the detectors to digital
signals, conditions those signals, and computes the required pressure information or decision data
using a set of algorithms implemented in firmware. The fabric is applied as computer input device,
medical device and devices in automotives [174].
The University of Sydney comprises an Optical Fibre Technology Centre, which was founded on silica
fibre fabrication. Thus, two major research fields at the centre are Silica Photonic Crystal Fibres and
Microstructured Polymer Optical Fibres (mPOF). Nowadays, they expanded their research activities
also to Fluoride Glass Optical Fibres [175].
The Geodetect system by Polyfelt ® Geosynthetics is a geotextile-based monitoring system. It consists
of a high strength textile, equipped with optical sensory fibres linked to a monitoring device and a PC.
The system is developed for the measurement of strain, allowing measuring the deformation and
absorbing behaviour of concrete reinforcements.
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