(K,Na)NbO3-LiNbO3 nanocube-based flexible and lead-free piezoelectric nanocomposite energy harvesters

Photothermal Structural Dynamics of Au Nanofurnace for In Situ Enhancement in Desorption and Ionization

“…In the presence of ultrasonic waves, the ZNT was subjected to stress, which resulted in positive/negative piezoelectric potentials on the tensile/compressive strained sides of the bent ZNT. [15,16] In addition, free electrons/holes were generated at the CB/VB of the ZNT photosensitizer by electromagnetic UV irradiation. Within the piezopotential well, the photogenerated electrons freely moved toward one ZNT interface with accumulated positive polarization charges, while holes were attracted to the other interface with negative polarization charges, which simultaneously tilted band edges in the ZNT.…”

“…[9][10][11][12] Since a short-pulse laser can instantly produce mechanical stress by generating a shock wave, [13,14] piezoelectric potential can be developed inside the ZnO crystal, which forces the free carriers to move in opposite directions and extends their lifetimes. [15][16][17] However, it still remains inefficient in ZnO matrix-based LDI-MS due to the following three critical challenges: 1) ZnO has little impact on the analyte desorption because its photothermal conversion efficiency is poor, even though the desorption is primarily driven by a thermal process; 2) the recombination rate of charge carriers is high because photoinduced electrons/holes have strong abilities for reduction/oxidation, and accordingly they recombine with each other at the end; and 3) the method to induce an internal stress high enough for enhanced LDI-MS is rather limited in a ZnO nanostructure.…”

Conformably Skin-Adherent Piezoelectric Patch with Bioinspired Hierarchically Arrayed Microsuckers Enables Physical Energy Amplification

“…KNN particles were well produced by a solid-state method, as shown by the X-ray diffraction pattern (Figure S3). KNN was selected as the proper piezoelectric material because it is a highly biocompatible and high-performance lead-free piezoelectric ceramic. , Note that the mechanically neutral plane of a flexible piezoelectric device should be positioned asymmetrically in the thickness direction by the different thicknesses or mechanics of the top and bottom substrates in order to induce an effective strain in bending motion. , We used 40 wt % of KNN particles as the filler as they are high-performance piezoelectric composite generators. , For composite-type energy harvesters, d 33 values have been used to evaluate piezoelectric properties . The d 33 piezoelectric coefficient of the manufactured piezoelectric composite film is 12.3 (±2.2) pC/N, which is similar to that of previous studies. , The piezoelectric signals were measured from the KNN-PDMS composite generator under bending and unbending motions in Figure .…”

“…19,20 Note that the mechanically neutral plane of a flexible piezoelectric device should be positioned asymmetrically in the thickness direction by the different thicknesses or mechanics of the top and bottom substrates in order to induce an effective strain in bending motion. 21,22 We used 40 wt % of KNN particles as the filler as they are highperformance piezoelectric composite generators. 21,23 For composite-type energy harvesters, d 33 values have been used to evaluate piezoelectric properties.…”

Progress in the Development of Single-Phase Magnetoelectric Multiferroic Oxides

“…있다. [1][2][3] 다강체(multiferroics)란 이러한 현상을 띠는 물질로, 이미 강유전과 강탄성이 공존 및 결합된 현상은 압전(piezoelectricity)라는 이름으로 지난 100여년의 세 월 동안 학문적으로 또 다양한 응용으로 연구되어왔다. 4) 반면, 강자성과 강유전성이 공존하는 형태인 자기전기 (magnetoelectric, ME) 다강체는 내재된 물리적 메커 니즘의 특이성 및 차세대 전자소자로의 활용 가능성으 로 인해 비교적 최근에 이르러서야 비로소 본격적으로 조명되고 있다.…”