Abstract: It is disclosed a composite yarn structure (10) comprising: —a first element (15) comprising a coaxial flexible bi-component monofilament including a conductive component (20) and a thermoplastic component (30) exhibiting piezoelectric properties, —at least a second element (40) twisted around the first element (15), wherein the second element (40) has a lower elasticity with respect to the elasticity of the first element (15) such that, upon elongation of the yarn structure (10) in a first direction, the yarn structure (10) expands in a second direction, whereby the dimensions of the yarn are increased both in first and second directions to generate an additional force on said piezoelectric component of the first element.

Abstract: It is disclosed a stretchable touchpad (10) of the capacitive type including a stretchable textile fabric (20) having a plurality of conductive elements incorporated therein. The conductive elements are resistive strain gauges (30, 40) which form electrodes to detect a change of capacitance caused by a touch. It is also disclosed a method for operating a stretchable touchpad (10) comprising the steps of measuring continuously a capacitance analog signal provided by a resistive strain gauge (30, 40) of the stretchable touchpad (10); and comparing the measured capacitance signal with a threshold value in order to determine whether or not a touch has taken place, wherein the threshold value is continuously adjusted as a function of the actual measurement of capacitance and as a function of the resistance of said resistive strain gauges (30, 40) which form the capacitor electrodes of said touchpad (10).

Abstract: It is disclosed a stretchable touchpad (10) of the capacitive type including a stretchable textile fabric (20) having a plurality of conductive elements incorporated therein. The conductive elements are resistive strain gauges (30, 40) which form electrodes to detect a change of capacitance caused by a touch. It is also disclosed a method for operating a stretchable touchpad (10) comprising the steps of measuring continuously a capacitance analog signal provided by a resistive strain gauge (30, 40) of the stretchable touchpad (10); and comparing the measured capacitance signal with a threshold value in order to determine whether or not a touch has taken place, wherein the threshold value is continuously adjusted as a function of the actual measurement of capacitance and as a function of the resistance of said resistive strain gauges (30, 40) which form the capacitor electrodes of said touchpad (10).

Abstract: It is disclosed a composite yarn structure (10) comprising: —a first element (15) comprising a coaxial flexible bi-component monofilament including a conductive component (20) and a thermoplastic component (30) exhibiting piezoelectric properties, —at least a second element (40) twisted around the first element (15), wherein the second element (40) has a lower elasticity with respect to the elasticity of the first element (15) such that, upon elongation of the yarn structure (10) in a first direction, the yarn structure (10) expands in a second direction, whereby the dimensions of the yarn are increased both in first and second directions to generate an additional force on said piezoelectric component of the first element.