Dielectrophoretic Preparation And Energy Harvesting Of BCZT/PDMS Flexible Composites

At present,wearable electronic devices such as health monitoring bracelets and smart glasses are widely used.Due to the size limitation,the continuous energy supply of these devices has limited their further development.Therefore,exploring a new energy supply method to replace the traditional battery energy supply has important research value.Flexible piezoelectric energy collector based on organic-inorganic piezoelectric composite material is a new energy technology,which can efficiently collect the mechanical energy generated by the human daily activities and convert it into electrical energy.It has important application prospects in the field of wearable electronic device energy supply.Compared with traditional piezoelectric ceramic materials,organic-inorganic piezoelectric composite materials have extremely high flexibility and fatigue resistance.However,due to the isolated distribution of piezoelectric particles and the mismatch of resistivity between two phases,randomly dispersed organic-inorganic piezoelectric composites generally exhibit lower piezoelectricity.In this paper,we prepared a barium calcium zirconate titanate/polydimethylsiloxane(BCZT/PDMS)piezoelectric composite with chain-like filler particles arranged by dielectrophoresis.The distribution of ceramic particles in a chain-like arrangement greatly improves the artificial polarization efficiency and stress transmission capacity of the composite material,thereby overcoming the inherent shortcomings of organic-inorganic composite materials.By optimizing the dielectrophoresis preparation process and polarization conditions,the material obtained a large piezoelectric voltage coefficient g₃₃=600×10^-3 Vm/N and conversion coefficient d₃₃×g₃₃=18.6 pm²/N.Through the power generation performance test,the open-circuit peak-peak voltage V_{OC(peak-peak)}=148 V and the short-circuit peak-peak current I_{SC(peak-peak)}=1.6?A can be obtained.In addition,we have developed a 3×3matrix self-powered wearable keyboard using this material.The keyboard shows high sensitivity and accuracy,and is expected to replace traditional keyboards in the field of wearable electronics.