Wenning Di

Dielectric, ferroelectric, and pyroelectric characterization of Mn-doped 0.74Pb(Mg1/3Nb2/3)O3-0.26PbTiO3 crystals for infrared detection applications

We investigated the dielectric, ferroelectric, and pyroelectric properties of Mn-doped 0.74Pb(Mg1/3Nb2/3)O3–0.26PbTiO3 crystals. Compared with pure PMN-0.26PT, Mn substitutions resulted in reduced dielectric loss and enhanced coercive field. Furthermore, the pyroelectric coefficient and detectivity figures of merits were enhanced to 17.2×10−4 C/m2 K and 40.2×10−5 Pa−1/2, respectively, which were the highest values so far reported among intrinsic pyroelectric materials with rhombohedral-tetragonal phase transition temperature greater than 90 °C. The specific detectivity of infrared detector based on Mn-doped crystals was 1.07×109 cm Hz1/2 W−1, and approximately doubles that of commercial LiTaO3 crystals-based, which makes them promising candidates for infrared detectors applications.

Bi-stable energy harvesting based on a simply supported piezoelectric buckled beam

Bi-stable piezoelectric energy harvester has been found as a promising structure for vibration energy harvesting. This paper presents a high performance and simple structure bi-stable piezoelectric energy harvester based on simply supported piezoelectric buckled beam. The potential energy function is established theoretically, and electrical properties of the device under different axial compressive displacements, excitation frequencies, and accelerations are investigated systematically. Experimental results demonstrate that the output properties and bandwidth of the bi-stable nonlinear energy harvester under harmonic mechanical excitation are improved dramatically compared with the traditional linear energy harvester. The device demonstrates the potential in energy harvesting application to low-power portable electronics and wireless sensor nodes.

Cantilever driving low frequency piezoelectric energy harvester using single crystal material 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3

We present a high performance piezoelectric energy harvester CANtilever Driving Low frequency Energy harvester (CANDLE) consisting of cantilever beam and cymbal transducers based on piezoelectric single crystal 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3. Electrical properties of CANDLE under different proof masses, excitation frequencies, and load resistances are studied systematically. Under an acceleration of 3.2g (g = 9.8 m/s2), a peak voltage of 38 V, a maximum power of 3.7 mW were measured at 102 Hz with a proof mass of 4.2 g. Low resonance frequency and high power output performance demonstrate the promise of the device in energy harvesting for wireless sensors and low-power electronics.

Scale Effects of Low‐Dimensional Relaxor Ferroelectric Single Crystals and Their Application in Novel Pyroelectric Infrared Detectors

Scaling effects of low-dimensional relaxor ferroelectric single crystals have induced large delocalization of domain switching, leading to a dramatic increase in pyro-electric performances by 2-5.5 times, and promoting the detectivity of fabricated pyroelectric detectors to an international leading level of 2.21 × 10(9) cmHz(1/2) /W at 10 Hz, 4 times higher than that of commercial LiTaO3 -based detectors.

Magnetoelectric voltage gain effect in a long-type magnetostrictive/piezoelectric heterostructure

We report a large voltage gain of 130, together with a high magnetoelectric voltage coefficient of 7.6 V/Oe, in a long-type heterostructure made by combining a coil-wound, length-magnetized magnetostrictive Tb0.3Dy0.7Fe1.92 (Terfenol-D) alloy plate and a length-polarized piezoelectric 0.7Pb(Mg1/3Nb2/3)O3–0.3PbTiO3 single-crystal plate along the length direction. The observed voltage gain is found to originate from the product effect of the electromagnetic induction in the coil and the resonance magnetoelectric effect in the heterostructure.

Parallel multilayer magnetoelectric composite based on (1−x)Pb(Mg1/3Nb2/3)−xPbTiO3 and Terfenol-D coupled with charge mode amplifier

In this paper, the sources and categories of noise regarding a charge mode magnetoelectric (ME) sensor are analyzed and simulated. A series of parallel multilayer magnetoelectric composites of Terfenol-D and (1−x)Pb(Mg1/3Nb2/3)−xPbTiO3 with different numbers of layers have been developed. The high magnetoelectric charge coefficients of these composites have been measured. By coupling different parallel multilayer magnetoelectric composites with a low noise-level chargeamplifier, we found that the noise equivalent magnetic induction (NEB) of the ME sensor based on the charge mode is in accordance with the theoretical prediction, and multilayers can reduce the NEB at low frequency and hardly at high frequency. At last we have established a new method of using high g 31piezoelectric material that can effectively reduce the influence of the operational amplifier voltage noise component and enhance resolution.

Magnetoelectric effect of the multi-push-pull mode in 0.35Pb(In1/2Nb1/2)O3-0.35Pb(Mg1/3Nb2/3)O3-0.30PbTiO3/Metglas magnetoelectric composite

This paper presents a model for the multi-push-pull configuration of magnetoelectric (ME) laminated composites which consist of magnetostrictive and piezoelectric layers with interdigitated ID electrodes encapsulated in Kapton. Analytical solutions for the ME voltage coefficient αV and charge coefficient αQ were derived. A ME composite has been made by magnetostrictive Metglas foils and piezoelectric 0.35Pb(In1/2Nb1/2)-0.35Pb(Mg1/3Nb2/3)-0.30PbTiO3 single crystal fibers, which exhibited a high ME charge coefficient αQ of 3756 pC/Oe at 1020 Hz. Besides showing a good linear relationship with AC magnetic field, the related ME sensor has a low noise equivalent magnetic induction of 10 pT/Hz1/2 at 1 Hz and 13 fT/Hz1/2 at resonant frequency.

Piezoelectric energy harvesting based on shear mode 0.71Pb(Mg 1/3 Nb 2/3 )O 3 -0.29PbTiO 3 single crystals

In this paper we theoretically and experimentally present a nonresonant vibration energy harvesting device based on the shear mode of 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 single crystals. The electrical properties of the energy harvesting device were evaluated using an analytical method. Good consistency was obtained between the analytical and experimental results. Under a mass load of 200 g, a peak voltage of 11.3 V and maximum power of 0.70 mW were obtained at 500 Hz when connecting a matching load resistance of 91 kΩ. A high output could always be obtained within a very wide frequency range. The results demonstrate the potential of the device in energy harvesting applied to low-power portable electronics and wireless sensors.

An improved magnetic field detection unit based on length-magnetized Terfenol-D and width-polarized ternary 0.35Pb(In1/2Nb1/2)O3-0.35Pb(Mg1/3Nb2/3)O3-0.30PbTiO3

A magnetoelectric laminate composite based on length-magnetized Terfenol-D alloy and width-polarized ternary 0.35Pb(In1/2Nb1/2)O3-0.35Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 single crystal has been developed and exhibits a giant magnetoelectric voltage coefficient of 1.7 V/Oe at low frequencies and 20 V/Oe at resonance frequency 84 020 Hz besides showing good linearity range of response in the field range of 1 pT-10 μT. Due to its small capacitance of 43 pF, a specially designed low-noise voltage follower was used to match the impedance. Based on the circuit, the detection limit of composite has been reached 1.9 pT/Hz1/2 at 1020 Hz and 300 fT/Hz1/2 at 84 020 Hz, respectively.

Excellent performances of energy harvester using cantilever driving double-clamped 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 plates and symmetric middle-stops

We present a high performance nonlinear piezoelectric energy harvester constituted by a cantilever with symmetrically middle-stops and double-clamped piezoelectric plates based on piezoelectric single crystal 0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3. Electrical properties of the device under different excitation frequencies, accelerations, and load resistances are studied systematically. Under a low acceleration of 3 m/s2 (0.3 g), a peak voltage of 26.2 V and a maximum normalized power of 25.6 mW/g2 were obtained across a matching impedance of 600 kΩ with favorable bandwidths. The low excitation acceleration and excellent performances indicate that the device can be a promising candidate for energy harvesting in low-power electronics and wireless sensors.