Molybdenum disulfide (MoS2) synthesized by Chemical Vapor Deposition (CVD) is commonly accompanied by some intermediate products in the form of MoO3-x, and causing MoS2-MoO3-x hybrids with diverse structures. In this...

Elucidation of complex structures of biomolecules plays a key role in the field of chemistry and life sciences. In the past decade, ion mobility, by coupling with mass spectrometry, has become a unique tool for distinguishing isomers and isoforms of biomolecules. In this study, we develop a concept for performing ion mobility analysis using an ion trap, which enables isomer separation under ultra-high fields to achieve super high resolutions over 10,000. The potential of this technology has been demonstrated for analysis of isomers for biomolecules including disaccharides, phospholipids, and peptides with post-translational modifications.

environmental sensors that eliminate costs and risks associated with recycling operations, [3] hardware secure data systems that would completely lose their functions when triggered through an instantaneous stimulus. [4] Organic semiconductors have been combined with polymer substrates to yield flexible, stretchable, and biodegradable systems, [5] while the modest carrier mobilities of organic active materials limit the performance that can be achieved. [6] Of the various bioresorbable materials employed in the most sophisticated biomedical systems, device-grade, monocrystalline silicon (Si) is of great interest owing to its potential to act as the basis for flexible high-performance transistors that align with conventional complementary metal-oxide-semiconductor (CMOS) technologies, [7] while forming minimally invasive interfaces to the soft and dynamic surfaces of targeted biological systems. [1h,3b,8] Moreover, highquality inorganic dielectrics, including silicon dioxide (SiO 2 ) and magnesium oxide (MgO) generally serve as the biodegradable gate dielectric materials in Si nanomembrane (NM) based transient microsystems. [9] However, the relatively low dielectric constant of the SiO 2 layer with sufficient thickness for long-term encapsulation from biofluids hinders the high-fidelity capacitive sensing and the scaling of the system. [10] Therefore, the introduction of high-k dielectrics will be critically important for realizing high-performance flexible and implantable electronics with capabilities in high-resolution amplification and fast multiplexed addressing. [11] As a key element of the stateof-the-art metal-oxide-semiconductor field-effect transistors (MOSFETs) using Si nanostructures (NSs) as building blocks, gate dielectrics play a vital role in determining the operating voltage, driving currents, and subthreshold characteristics. [12] Table 1 systematically compares the electrical properties of Si NS based MOSFETs with various gate dielectrics. The development of high-performance Si NS based MOSFETs has been frustrated by the primary limitations that some hightemperature fabrication steps such as the gate dielectric deposition are incompatible with the flexible substrates. To address this issue, Si NS based MOSFETs have been fully fabricated on the native substrates on which high-temperature deposition of Emerging transient electronics offer great potential in eco-friendly and bioresorbable electronic applications. In this study, bendable and biodegradable metal-oxide-semiconductor field-effect transistors (MOSFETs) and metal-oxide-semiconductor capacitors (MOSCAPs) have been fabricated by integrating HfO 2 /Al 2 O 3 high-k bilayers on the transferred silicon nanomembranes (Si NMs) and utilizing PLGA-gelatin-chitosan polymeric substrates. The transient n-channel MOSFETs demonstrate high effective mobility of 871 cm 2 V −1 s −1 , high on-state current of 27.6 µA µm −1 , high on/off current ratio > 10 7 , and low gate leakage current ≤2.7 × 10 −7 A cm −2 . The accumulation capacitance of the trans...

The extracellular matrix (ECM) of natural cells typically exhibits dynamic mechanical properties (viscoelasticity and dynamic stiffness). The viscoelasticity and dynamic stiffness of the ECM play a crucial role in biological processes, such as tissue growth, development, physiology, and disease. Hydrogels with viscoelasticity and dynamic stiffness have recently been used to investigate the regulation of cell behavior and fate. This article first emphasizes the importance of tissue viscoelasticity and dynamic stiffness and provides an overview of characterization techniques at both macro- and microscale. Then, the viscoelastic hydrogels (crosslinked via ion bonding, hydrogen bonding, hydrophobic interactions, and supramolecular interactions) and dynamic stiffness hydrogels (softening, stiffening, and reversible stiffness) with different crosslinking strategies are summarized, along with the significant impact of viscoelasticity and dynamic stiffness on cell spreading, proliferation, migration, and differentiation in two-dimensional (2D) and three-dimensional (3D) cell cultures. Finally, the emerging trends in the development of dynamic mechanical hydrogels are discussed.

Flexible metal-oxide-semiconductor capacitors in a vertical structure using the single-crystalline Si nanomembrane (NM) with a HfO2/Al2O3 bilayer gate stack prepared by atomic layer deposition have been fabricated on plastic substrates by flip-transfer printing of Si NM/Ti/Au based trilayer heterostructures (1.3 cm × 0.9 cm × 360 nm). The electrical properties of the bilayer structure exhibit an excellent improved capacitance-voltage (C-V) frequency dispersion feature associated with an inhibited weak inversion hump and significantly larger accumulation capacitance, thus indicating the effectiveness of the passivation utilizing bilayer high-k dielectrics on a Si NM channel compared with monolayer HfO2. A comprehensive electromechanical characterization has been conducted for HfO2/Al2O3 stacked structures to investigate the effect of bending strain on C-V characteristics, leakage current density, and the associated evolution of interface charges. The presented research will be beneficial to realizing high performance thin-film transistors with lower operating voltage and higher driving current required in emerging flexible and stretchable electronics via optimized design of a nanolaminate gate stack and understanding the impact of mechanical strains on the electrical behavior of such MOS devices.