Clevertex - Grado Zero Espace Srl

more compact and lightweight. Next to bending capabilities of 360°, flexible circuitry offers reduced
circuit sizes. Further, the use of conductive inks for flexible printed circuits has increased in popularity
because they have a substantial price advantage over other plating methods.
The National Textile Center of the North Carolina State University is currently working on a project
dealing with ‘Printing Electric Circuits on Non-Woven Fabrics’ used to produce a prototype for a
physiological monitoring garment that measures ECG, heart-rate, respiration and temperature. In the
scope of the project they work together with conductive ink manufacturers. For their experimental
investigations and to succeed in producing samples of antennas having been printed on non-woven
textile structures, they use Evolon ® by Freudenberg KG, Tyvek ® by DuPont, FiberWeb Resolution
Print Media by BBA FiberWeb, as well as conductive inks donated by Precisia LLC and Creative
Materials Inc.[35].
2.1.3 Enabling technologies
The different technologies discussed previously are used to produce textile materials with the ability to
conduct electricity. Components including input and output devices, sensors, data processing devices,
data storage devices and power supplies provide necessary technologies for interaction, hence
creating an electronic textile.
Input devices including keyboards and switches are two examples beings explored for interactive
electronic textile data entry.
The output devices being explored for displaying data include Cathode Ray Tubes (CRT’s) and Liquid
Crystal Displays (LCD’s), but also mirror displays and flexible light emitting displays. An overview of
textile displays and research work being done in this field is discussed in chapter 2.3 [36].
2.1.3.1 Conductive materials as sensors
Sensors add features and functionality to electronic textiles. Conductive textiles that change their
electrical properties as a result of environmental impact can be used as sensors. Typical examples are
textiles that react to deformation such as pressure sensors, stretch sensors and breathing sensors.
2.1.3.1.1 Pressure sensors
Pressure sensors are commonly used either to monitor vital signs of the user, such as heart rate,
blood pressure or the user’s motion, or also to use them as switches and interfaces to control
17