smart materials in renewable energy applications - CUEN

SMART MATERIALS IN RENEWABLEENERGY APPLICATIONSProf. Elias SioresInstitute for Materials Research andInnovation IMRI

Piezoelectricity• Capability to transform mechanical energy into electricalenergy and vice versa is know as “piezoelectricity”.• Direct Piezoelectric Effect• Converse Piezoelectric EffectNOTION BY CHARLES COLOUMB, 1817PIERRE & JACQUES CURIE, 1880NAME GIVEN BY HANKEL, 1881PIEZOELECTRICITY OF BaTiO3, 1946LEAD ZIRCONATE TITANATE (PZT), 1952PIEZOELECTRICTY OF POLYVINYLIDENE FLUORIDE (PVDF) BY KAWAI, 1969

Naturally OccurringPiezoelectric Materials• Bone• Tendon• Silk• Wood• Enamel• Cane sugar• Tourmaline• Rochelle salt• Berlinite• Quartz etc.

Man Made Piezoelectric MaterialsPiezoelectric Ceramics• Barium titanate (BaTiO3)• Lead titanate (PbTiO3)• Lead-zirconate (PbZrO 3 )• Lead zirconate titanate (PZT)• Sodium tungstate (Na2WO3)• Lithium tantanate (LiTaO3)• Lithium niobate (LiNbO3)• Potasium niobate (KNbO3)• Ba2NaNb5O5• Pb2KNb2O15Piezoelectric Polymers• Polyvinylfluoride (PVF)• Polyvinylidene fluoride (PVDF)• Porous Polypropylene (PP)• Fluoroethylenepropylene (FEP)• Polytetrafluoroethylene (PTFE)• Cellular cycloolefines (COC)• Cellular polyethylene terephthalate(PETP)

Need to produce flexiblepiezoelectric fibres because…Existing piezoelectric fibres• lead-zirconate titanate (PZT) based, are• rigid,• Brittle,• Environmentally unfriendlyExisting flexible piezoelectric structures• polyvinylidene fluoride (PVDF) based, are• commercially available only in film form‣ None of these commercial piezoelectric materials are suitable to be used intextiles thus providing 2-D and 3-D structures in big scale.

Schematic of a Melt Extruder PiezoelectricFilament Extrusion Process

Piezoelectric Filament ProductionNon-polar polymer filamentPiezoelectric polymer filament

What happens…?Application of;• High stretching ratio•High voltage•Elevated temperatureCauses;Phase change fromnon-polar alpha phaseα-phaseto polar beta phasesβ-phase

SEM Images for Unpoled and PoledPVDF FibresSEM Image of unpoled PVDF fibreSEM Image of poled PVDF fibre

Piezoelectric Filaments Produced viaa continuous process at IMRIMulti-FilamentMono-FilamentRibbon

Possible Woven Structurespiezoelectric thread, conductive thread, non-conductive thread

Preparation of Test Specimens

Instron Dynatup 9200 Impact TestEquipment

Why Hybrid Piezoelectric Photovoltaic(HPP) Films and Fibres?‣ Piezoelectric materials can convert mechanicalenergy to electrical energy, but if there is nomechanical stimuli…?‣ Photovoltaic materials can convert sun light toelectrical energy, but if there is no sun light...?‣ HPP technology offers almost undisturbedenergy generation by combining these twosmart technologies into single fibre material.

Production Process of HybridFilms & FibresPiezoelectric film/fibre withelectrodes and insulatorlayerDrying andAnnealingElectrodeEvaporationElectrodeEvaporationBuffer LayerProtectiveLayerActive LayerDrying andAnnealingDrying

Principle of Spin CoatingProcess• Piezoelectric substrate• Electrode• P3HT:PCBM• PEDOT:PSS• Electrode

HPP Materials Produced at IMRI

Hybrid Fibre and Film

Power Conversion EfficiencyMeasurement

Wind tunnelexperiments6010050Power (µW)80604020PZT-bimorphPZT-singleLDT4-28KPeak voltage (V)403020LDT1-28KLDT1-28K/OPV0100.995 9.75 78.8 388.1 782 1571 3144Load (kΩ)00 2 4 6 8 10 12Wind speed (m/sec)

Electronic CircuitryVoltage generated by the piezoelectricmaterial will be fluctuating with randomfrequency. This signal needs to be convertedto a standard DC voltage.This is done using a full wave rectifier and acapacitor. By using complex circuits we canimprove the conversion efficiency.

Integrated Chip and StorageHigh efficiency AC to DCconverter ICSupercapacitorfor storageVoltage generated by the piezoelectric material will be fluctuating with randomfrequency. This signal needs to be converted to a standard DC voltage.This is done using a full wave rectifier and a capacitor. By using complex circuitswe can improve the conversion efficiency.

PotentialApplications

Energy harvesting from Carpet 3-D Structure

Energy Harvesting from Roof Top LiningsPiezoelectric-Photovoltaic hybridstructures can be used toproduce roof top liningswhich can produceenergy from sun, rainand wind depending onthe designrequirements.

CurtainsOrganic photovoltaic or piezoelectricphotovoltaichybrid fibre structures can beused to produce curtains or curtain-likestructures to generate electricity from sunlight as well as motion.

Lamp posts, garden lights, trafficlights, bus stop shelters, train stationsSolar lamps have been in use foryears. Solar cells are extensivelyused to power decorative gardenlights or even traffic lights.PiezoelectricpartPhotovoltaic partIf these are replaced with hybridstructures, harvested energy willbe higher since the conversion willbe from both mechanical toelectrical energy as well as fromsolar to electrical.Hybrid structures can be used inalmost any areas that solar panelsare used.

Conclusions‣ For the first time a flexible piezoelectric filament has been successfullyproduced via a continuous process by applying a high stretching ratio, heatand high voltage, simultaneously. (International Patent)‣ For the first time flexible hybrid piezoelectric-photovoltaic film and fibrehave been successfully produced and tested. (International Patent)‣ Additionally, a rectifying circuit consisting of an IC, 4 diodes and acapacitor can be used to rectify the fluctuating voltage of variousfrequencies to a constant DC voltage obtained from the Piezoelectric andthe Organic Photovoltaic outputs. (International Patent)‣ The constant voltage generated and rectified can then be either stored inan electrical storage device such as batteries or super capacitors or can beutilised on-line directly.‣ 2 International Awards have been obtained.‣ FibrLec company established in 2013 – From Laboratory tocommercialisation.

Thanks for your attention !es3@bolton.ac.uk