Energy Storage Capacity and Electrocaloric Effect on Sn Modified Barium Titanium Oxide (BaTi0.8Sn0.2O3)

Modified Barium Titanium Oxide ( BaTi 0.8 Sn 0.2 O 3 ) was prepared by using the solid-state reaction method. The crystal structure, energy storage behavior, and electrocaloric properties were studied. The phase purity and structural analysis were investigated using the X-ray diffraction technique and the Rietveld refinement of XRD pattern. The microstructure of the sample was recorded by using the Field Emission Scanning Electron Microscopy (FESEM). The temperature variation dielectric property shows that the ceramic exhibits diffuse phase transition behaviour. The ferroelectric nature in BaTi 0.8 Sn 0.2 O 3 has been depicted from P-E loops analysis. The energy storage behaviour and electrocaloric properties were estimated from the temperature variation P-E loops at 40kV/cm. The electrocaloric effect was studied by an indirect method using Maxwell relation, and the electrocaloric value has been estimated to with 94% of energy storage efficiency.

Analysis of perovskite oxides etching using argon inductively coupled plasmas for photonics applications

We analyzed the dry etching of perovskite oxides using argon-based inductively coupled plasmas (ICP) for photonics applications. Various chamber conditions and their effects on etching rates have been demonstrated based on Z-cut lithium niobate (LN). The measured results are predictable and repeatable and can be applied to other perovskite oxides, such as X-cut LN and barium titanium oxide (BTO). The surface roughness is better for both etched LN and BTO compared with their as-deposited counterparts as confirmed by atomic force microscopy (AFM). Both the energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) methods have been used for surface chemical component comparisons, qualitative and quantitative, and no obvious surface state changes are observed according to the measured results. An optical waveguide fabricated with the optimized argon-based ICP etching was measured to have − 3.7 dB/cm loss near 1550 nm wavelength for Z-cut LN, which validates this kind of method for perovskite oxides etching in photonics applications.

Analysis of perovskite oxide etching using argon inductively coupled plasmas for photonics applications

We analyzed the dry etching of perovskite oxides using argon-based inductively coupled plasmas (ICP) for photonics applications. Various chamber conditions and their effects on etching rates have been demonstrated based on Z-cut lithium niobate (LN). The measured results are predictable and repeatable and can be applied to other perovskite oxides, such as X-cut LN and barium titanium oxide (BTO). The surface roughness is better for both etched LN and BTO compared with their as-deposited counterparts as confirmed by atomic force microscopy (AFM). Both the energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) methods have been used for surface chemical component comparisons, qualitative and quantitative, and no obvious surface state changes are observed according to the measured results. An optical waveguide fabricated with the optimized argon-based ICP etching was measured to have -3.7 dB/cm loss near 1550 nm wavelength for Z-cut LN, which validates this kind of method for perovskite oxides etching in photonics applications.

Analysis of Perovskite Oxides Etching Using Argon Inductively Coupled Plasmas for Photonics Applications

We analyzed the dry etching of perovskite oxides using argon-based inductively coupled plasmas (ICP) for photonics applications. Various chamber conditions and their effects on etching rates have been demonstrated based on Z-cut lithium niobate (LN). The measured results are predictable and repeatable and can be applied to other perovskite oxides, such as X-cut LN and barium titanium oxide (BTO). The surface roughness is better for both etched LN and BTO compared with their as-deposited counterparts as confirmed by atomic force microscopy (AFM). Both the energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) methods have been used for surface chemical component comparisons, qualitative and quantitative, and no obvious surface state changes are observed according to the measured results. An optical waveguide fabricated with the optimized argon-based ICP etching was measured to have -3.7 dB/cm loss near 1550 nm wavelength for Z-cut LN, which validates this kind of method for perovskite oxides etching in photonics applications.

Elastomer Transducers

Electroactive polymer transducers have many features that are desirable for various devices. An especially attractive type of electroactive polymer is dielectric elastomer (DE). Our recent progress is a DE actuator having only 0.1 g of DE that lifted a weight of 2 kg using carbon system electrodes. We also developed a ribbon form DE actuator having a sensor function that can be used to measure force, or pressure, as well as motion at the same time. This actuator can assist human and robot motions. At the same time, it can work as a motion feedback sensor. We hope that it may be useful for smart rehabilitation equipment for hands, legs, and fingers. DE has also been shown to operate in reverse as a generator. Experiments have been performed on portable DE generators/wearable generators powered by human motion, ocean wave power harvesters mounted on buoys, solar heat generators, and water turbines. While the power output levels of such demonstration devices is small, the performance of these devices has supported the potential benefits of DE. We are developing elastomers having larger dielectric constant using barium titanium oxide to produce a “super artificial muscle for energy harvesting devices, actuators & sensors” in the near future.

Frequency and temperature dependence of dielectric and electric properties of Ba2-xSm4+2x/3Ti8O24 with structural analysis

Dielectric ceramics samples of barium titanium oxide doped with samarium, having a complex structural formula of Ba2-xSm4+2x/3Ti8O24 (referred to as BST), were fabricated by a high temperature solid-state reaction technique with varying x (0.0, 0.2, 0.4, 0.6). X-ray diffraction technique was used to check the formation of particular phases. Scanning electron microscope technique was used to study the surface morphology of the samples. The samples were studied in a temperature range of 298 K to 623 K and frequency range of 10 KHz to 1 MHz. The dielectric constant (εr), loss tangent (tan δ), and AC conductivity (σAC) were measured on sintered disks of BST samples. The DC resistivity of different compositions was measured at room temperature. Detailed studies of dielectric and electrical properties showed that these properties are strongly dependent on composition, frequency and temperature. The compounds showed stable behavior in lower temperature range (up to 523 K), therefore, they can be used in practical applications in this temperature range.

Effect of Silver Coating on Barium Titanium Oxide Nanoparticle Toxicity

Nanoparticles are presently being studied for optical and biomedical applications such as medical imaging and drug delivery. Nanoparticles impact the cellular environment due to many variables such as size, shape, and composition. How these factors affect cell viability is not fully understood. The purpose of this study is to test the toxicity effects of silver coating (Ag@) Barium Titanium Oxide (BaTiO3) nanoparticles on Rhesus Monkey Retinal Endothelial cells (RhRECs) in culture. The addition of silver to the nanoparticles increases their nonlinear optical properties significantly, making the Ag@BaTiO3 nanoparticles good candidates for nonlinear microscopy contrast agents. We hypothesize that by silver coating nanoparticles, there will be an increase in cell viability at higher concentrations when compared to non-silver coated nanoparticles. RhRECs were treated with BaTiO3 and Ag@BaTiO3 at concentrations of 0, 1.0, 10.0, and 100μg/ml for 24 hours at 370C + 5%CO2. After 24 hour incubation with respective nanoparticles, cell viability was determined using the trypan blue dye-exclusion method. Treatment with 0, 1.0 and 10.0μg/ml of Ag@BaTiO3 had minimal effect on cell viability, with 90% viable cells remaining at the end of the 24 hours treatment period. However, cells treated with 100μg/ml of Ag@BaTiO3 resulted in a decrease to 51% viable cells. Comparatively, cells treated with 0, 1.0 and 10μg/ml of BaTiO3 had no significant effect on cell viability (90% viable cells after treatment) while the 100μg/ml treatment resulted in a decrease to 29% viable cells. These results show that silver coating of BaTiO3 nanoparticles has a protective effect on cellular toxicity at high concentrations.