Controllable preparation of helically structured polymer nanobelts by simple writing

A simple direct writing technique is developed for preparing helically structured nanobelts. The geometric asymmetry and surface strain contribute to the formation of helical structure. The shape of the helically structured nanobelts can be tuned by the nozzle size of micropipette and pulling speed. The applicability and generality of this technique are illustrated by successfully preparing the helical nanobelts of PPy, PVP, PVDF-TrFE, PEG, PMVE-MA and PVA. The potential applications of such helical structures in the area of sensor and energy harvesting are also demonstrated.