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In recent years, implantable medical devices (IMDs) have introduced groundbreaking solutions for managing various health conditions. However, traditional implanted batteries necessitate periodic surgical replacement and tend to be relatively bulky, posing significant inconvenience to patients. To overcome these limitations, researchers have investigated various wireless power transfer (WPT) techniques, among which the ultrasonic wireless power transmission (UWPT) technique has distinct advantages. However, limited research has been conducted on ultrasonic power transfer at lower operating frequencies. Therefore, this study explores wireless power transfer using scandium-doped aluminum nitride (AlScN) piezoelectric micro-electromechanical transducers (PMUTs) in deionized (DI) water. Experimental results indicate that at an operating frequency of 14.075 kHz, the power transfer efficiency (PTE) can reach up to 2.68% under optimal load resistance conditions. Furthermore, a low-frequency UWPT system based on a AlScN PMUT has been developed, delivering a stable 3.3 V output for implantable medical devices and contributing to the advancement of a full-spectrum UWPT framework.
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http://dx.doi.org/10.3390/mi16040471 | DOI Listing |
Gait Posture
September 2025
School of Business, Social and Decision Sciences, Constructor University Bremen, Constructor University, Campus Ring 1, Bremen 28759, Germany.
Background: Age-related declines in dynamic balance and cognitive control increase fall risk in older adults (OA). Non-invasive brain stimulation, such as anodal transcranial direct current stimulation (a-tDCS), may enhance training outcomes. However, it remains unclear whether stimulation over motor or prefrontal regions is more effective for improving dynamic balance training (DBT) in OA.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
September 2025
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012, P.R. China.
Neutral aqueous Zn-air batteries (ZABs), while promising for extended lifespans and recyclability compared to alkaline systems, are hindered by sluggish kinetics that limit energy efficiency and power output. Here, we report an effective approach to construct a photo-assisted near-neutral ZAB based on a photo-responsive titanium silicalite-1 zeolite (TS-1). The incorporation of Ru active centers into the 3D porous architecture of TS@C (Ru@TS@C), which exhibits remarkably enhanced electronic conduction, creates interconnected conductive pathways.
View Article and Find Full Text PDFHum Reprod
September 2025
Boston IVF-IVIRMA Global Research Alliance, Waltham, MA, USA.
Study Question: Does a high proportion of immature oocytes impact embryo development and live birth rates in IVF-ICSI cycles?
Summary Answer: While a high proportion of immature oocytes is associated with lower blastocyst formation and reduced preimplantation genetic testing for aneuploidy (PGT-A) utilization, live birth rates remain comparable when key confounders-such as age, BMI, gonadotropin dosage, and metaphase-II (MII) count-are balanced, but cycles with a very low MII proportion resulted in fewer embryo transfers, which is quantitatively limiting, even if embryo quality appears unaffected.
What Is Known Already: Previous studies have linked a lower proportion of mature oocytes (MII) to decreased fertilization rates, abnormal embryo development, and lower pregnancy and live birth rates. However, it remains unclear whether these outcomes are due to quantitative limitations (fewer mature oocytes available) or qualitative deficiencies (intrinsic oocyte quality issues).
ACS Appl Mater Interfaces
September 2025
Center for Graphene Research and Innovation, University of Mississippi, University, Mississippi 38677, United States.
To assess the efficacy of a mixed-dimensional van der Waals (vdW) heterostructure in modulating the optoelectronic responses of nanodevices, the charge transport properties of the transition-metal dichalcogenide (TMD)-based heterostructure comprising zero-dimensional (0D) WS quantum dots (QDs) and two-dimensional (2D) MoS flakes are critically analyzed. Herein, a facile strategy was materialized in developing an atomically thin phototransistor assembled from mechanically exfoliated MoS and WS QDs synthesized using a one-pot hydrothermal route. The amalgamated photodetectors exhibited a high responsivity of ∼8000 A/W at an incident power of 0.
View Article and Find Full Text PDFSmall
September 2025
State Key Laboratory of Flexible Electronics (LoFE) & Institute of Flexible Electronics (IFE), Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, 710072, P. R. China.
Flexible strain sensors are pivotal for the advancement of robotics, wearable healthcare, and human-machine interaction in the post-Moore era. However, conventional materials struggle to simultaneously achieve high sensitivity, a broad strain range, and low power consumption for cutting-edge applications. In this work, the issue is addressed through single crystal 1D tellurium nanoribbons (NRs), which are synthesized on SiO/Si substrate by hydrogen-assisted chemical vapor deposition (CVD) method.
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