Transferred PMN-PT Thick Film on Conductive Silver Epoxy

Approximately 25 μm Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN-PT) thick film was synthesized based on a sol-gel/composite route. The obtained PMN-PT thick film was successfully transferred from the Silicon substrate to the conductive silver epoxy using a novel wet chemical method. The mechanism of this damage free transfer was explored and analyzed. Compared with the film on Silicon substrate, the transferred one exhibited superior dielectric, ferroelectric and piezoelectric properties. These promising results indicate that transferred PMN-PT thick film possesses the capability for piezoelectric device application, especially for ultrasound transducer fabrication. Most importantly, this chemical route opens a new path for transfer of thick film

Research Advance in the Regulatory Mechanism of Phytohormone for Plant Responses to Aluminum Toxicity Stress

Aluminum is the most abundant metal element in the crust. Soil acidification will cause great increase of the aluminum solubility to produce a large number of Al3+, which is toxic to plants. The activated aluminum will inhibit root growth, affect nutrient absorption and many physiological and biochemical metabolism processes, and further reduce crop yield. Aluminum toxicity has been the most important limiting factor for crop growth in acid soils which account for about 40% of cultivated land in the world. Phytohormones are the key endogenous factors that regulate plant responses to various environmental stresses, and are crucial to the improvement of plant resistance and plant survival under various stresses. It is well known that abscisic acid, auxin, ethylene, cytokinin, jasmonic acid and other major plant hormones play an important role in regulating plant responses to aluminum toxicity stress. A large number of studies have shown that plant hormones can also improve the adaptability of plants to aluminum stress by regulating the activities of cell wall-modifying enzymes, reactive oxygen species metabolism and organic acid secretion. In addition, there are complex interactions between different plant hormone signals, which jointly mediate and regulate the adaptive response of plants to aluminum stress. In order to have a more comprehensive and in-depth understanding of the mechanism of plant hormones in aluminum toxicity response, and to provide new ideas for molecular genetic improvement of plants tolerance to aluminum toxicity, in the study, the signal transduction and regulation of plant hormone signals in the process of plant response to aluminum toxicity stress are reviewed, and the future research direction of plant hormones under aluminum toxicity stress is prospected

Polyploidization Genetic Mechanism of Sugarcane Genome

The sugarcane genome polyploidization can reduce the pressure of gene evolution selection, promote the fixation of fine traits, and increase the biomass and economic value of sugarcane. This paper mainly introduced the origin of the sugarcane genome, the chromosome composition, the research progress of polyploidization genetic mechanism, in the hope of providing theoretical reference for sugarcane polyploidization breeding

A Self-Healing Optoacoustic Patch with High Damage Threshold and Conversion Efficiency for Biomedical Applications

Highlights Based on Fe-Hpdca-PDMS and carbon nanotube composite, an optoacoustic patch is developed, which can recover from the damage induced by cutting or laser irradiation at room temperature. The patch has high laser damage threshold (183.44 mJ cm−2) and optoacoustic energy conversion efficiency (10.66×10−3). The patch has been successfully examined in acoustic flow, thrombolysis, and wireless energy harvesting, which may provide new insights into the field of the design and fabrication of novel ultrasound devices for biomedical applications

Lead halide perovskite for efficient optoacoustic conversion and application toward high-resolution ultrasound imaging

Lead halide perovskites are widely used e.g. in solar cells and LEDs, but devices based on thermal properties have received little attention. Here, the authors take advantage of the thermal properties to fabricate an optoacoustic transducer with both broad bandwidth and high conversion efficiency

Micro-particle manipulation by single beam acoustic tweezers based on hydrothermal PZT thick film

Single-beam acoustic tweezers (SBAT), used in laboratory-on-a-chip (LOC) device has promising implications for an individual micro-particle contactless manipulation. In this study, a freestanding hydrothermal PZT thick film with excellent piezoelectric property (d33 = 270pC/N and kt = 0.51) was employed for SBAT applications and a press-focusing technology was introduced. The obtained SBAT, acting at an operational frequency of 50MHz, a low f-number (∼0.9), demonstrated the capability to trap and manipulate a micro-particle sized 10μm in the distilled water. These results suggest that such a device has great potential as a manipulator for a wide range of biomedical and chemical science applications

Self-Focused AlScN Film Ultrasound Transducer for Individual Cell Manipulation

Precise cell positioning is indispensable in the fields of biophysics and cellular biology. Acoustic microbeam produced by a highly focused ultrasound transducer has recently been investigated for a particle or cell manipulation. By virtue of the relatively good piezoelectric property, Sc doped AlN film was introduced for a highly focused ultrasound transducer application. Using a sputtering approach, a self-focused AlScN film based device has been designed, fabricated, and characterized at a frequency of ∼230 MHz. It had a narrow lateral beam width (∼8.2 μm). The AlScN ultrasound transducer was not only shown to be capable of remote controlling a single 10 μm polystyrene microsphere in distilled water, but also demonstrated to possess the capability to manipulate without contact individual 10 μm epidermoid carcinoma cell in two dimensions within a range of hundreds of micrometers in phosphate buffered saline. Most importantly, the cell manipulation was realized in continuous mode and no switch-on and -off operation was needed. These results suggest that self-focused AlScN film ultrasound transducer is a promising candidate for biomedical and molecular biology applications