This sensor takes some time to make. Repeatedly threading, stitching and cutting thread. But the result is quite effective and you can vary the design of the sensor in order to detect different kinds of stroke. See illustration for variations in stroke sensor design.
Various techniques could be applied to create this kind of "stroke sensor" such as knitting or crocheting loop stitch or rug knotting techniques. This Instructable shows how to stitch conductive 117/17ply silver plated nylon thread and a more resistive 66 Yarn 22+3ply 110 PET thread into neoprene in order to create a "stroke sensor". The rubberiness of the neoprene creates enough friction so that the threads will not come loose when stroking. Meaning you don't have to knot each individual hair. It is important to use these particular threads as thicker conductive threads tend to curl when repeatedly stroked and thus don't work for the stroke sensing anymore.