FIG. 3. Scheme of the autocoiling process for NC: a) The precursor fibre has the top end fixed to a motor, and the bottom end
rigidly attached to a weight which is prevented from rotation and is free to slide up and down. b) As the motor starts rotating,
the fibre is twisted. The fibre visibly shortens. c) Coiling is generated by mechanical instability (autocoiling). d) When the
whole length is coiled, the motor is stopped. e) The NC is fixed on a rigid frame. f) A heat treatment fixes the shape. g) The
NC is ready.