TY - JOUR
AU1 - Guo, X D
AU2 - Helseth, L E
AB - We report how self-assembly of polyelectrolyte thin films alters the contact electrification of polyimide polymer films used in contact based triboelectric energy harvesting systems. Polyimide films of the same size do produce a very small current when brought into contact. However, by covering one of the polyimide films with a polyelectrolyte thin film terminated by positively charged poly(allylamine hydrochloride) (PAH), the current is reversed and a much larger current and voltage are generated upon contact with the other polyimide film. A similar increase in contact current is not seen for polyelectrolyte thin films terminated by the negatively charged poly(sodium 4-styrenesulfonate). The PAH-terminated Kapton films are used to create an energy harvesting system providing a voltage of about 60 V and a current of 10 μA. At an average power of 11 μW for a load resistance of 100 MΩ, the energy harvester is able to power several light emitting diodes. Further studies on the contact electrification of the polyelectrolyte demonstrate that nanostructuring of the polymer surface using reactive ion etching does not give rise to polarity reversal. This is explained as hidden pockets of charge not accessible to PAH molecules, but which become accessible when the polymer is put under stress. Although the current originating for a PAH-terminated multilayer film does initially have the opposite sign to that of bare polyimide, it is found that the polarity will switch after subjecting it to a periodical mechanical force. Characteristic changes in current signatures associated with the switch are found, and are interpreted as mechanical interpenetration of the charged layers.
TI - Layer-by-layer polyelectrolyte films for contact electric energy harvesting
JF - Journal of Physics D: Applied Physics
DO - 10.1088/0022-3727/48/7/075302
DA - 2015-02-25
UR - https://www.deepdyve.com/lp/iop-publishing/layer-by-layer-polyelectrolyte-films-for-contact-electric-energy-S74RvTmzsG
SP - 075302
VL - 48
IS - 7
DP - DeepDyve
ER -