A Novel Hollow Graphene/Polydimethylsiloxane Composite for Pressure Sensors with High Sensitivity and Superhydrophobicity.

Flexible pressure sensors have attracted great interest as they play an important role in various fields such as health monitoring and human-machine interactions. The design of the pressure sensors still faces challenges in achieving a high sensitivity for a wide sensing range, and the interference of water restricts the applications of the sensors. Herein, we developed a graphene-polydimethylsiloxane film combining a hierarchical surface with nanowrinkles on it and a hollow structure.

SnS Quantum Dot-Based Optoelectronic Flexible Sensors for Ultrasensitive Detection of NO Down to 1 ppb.

Transition-metal dichalcogenides (TMDs) have gained intense interest for their outstanding optoelectronic and electrochemical characteristics, utilized in versatile applications such as gas sensors and photodetectors. However, TMD-based chemiresistors suffer from poor sensitivity at ppb-level detection, and the experimental detection limit fails to reach 1 ppb. Herein, SnS QD/graphene nanoheterostructures as functional flexible sensors are fabricated for NO gas and light detection at room temperature.

High Sensitivity, Humidity-Independent, Flexible NO and NH Gas Sensors Based on SnS Hybrid Functional Graphene Ink.

Here, a high sensitivity gas sensing ink based on sulfonated rGO (S-rGO) decorated with SnS is synthesized for room temperature NO and NH detection. This sensing ink demonstrated an excellent sensitivity to ppb-level NO (17% response to 125 ppb) and sub-ppm-level NH (11% response to 1 ppm). The unique absorption properties of SnS improve the sensitivity of S-rGO 4.

Study on Damage Evaluation and Machinability of UD-CFRP for the Orthogonal Cutting Operation Using Scanning Acoustic Microscopy and the Finite Element Method.

Owing to high specific strength and designability, unidirectional carbon fiber reinforced polymer (UD-CFRP) has been utilized in numerous fields to replace conventional metal materials. Post machining processes are always required for UD-CFRP to achieve dimensional tolerance and assembly specifications. Due to inhomogeneity and anisotropy, UD-CFRP differs greatly from metal materials in machining and failure mechanism.

Calibrating conservative and dissipative response of electrically-driven quartz tuning forks.

Determining sensor parameters is a prerequisite for quantitative force measurement. Here we report a direct, high-precision calibration method for quartz tuning fork (TF) sensors that are popular in the field of nanomechanical measurement. In the method, conservative and dissipative forces with controlled amplitudes are applied to one prong of TF directly to mimic the tip-sample interaction, and the responses of the sensor are measured at the same time to extract sensor parameters.

Biomimic Hairy Skin Tactile Sensor Based on Ferromagnetic Microwires.

We present a multifunctional tactile sensor inspired by human hairy skin structure, in which the sensitive hair sensor and the robust skin sensor are integrated into a single device via a pair of Co-based ferromagnetic microwire arrays in a very simple manner. The sensor possesses a self-tunable effective compliance with respect to the magnitude of the stimulus, allowing a wide range of loading force to be measured. The sensor also exhibits some amazing functions, such as air-flow detection, material property characterization, and excellent damage resistance.

Oxidative etching of MoS/WS nanosheets to their QDs by facile UV irradiation.

Oxidative etching has been proved to be an efficient top-down method to prepare quantum dots (QDs) of layered transition-metal dichalcogenides which possess unique properties and have potential applications in various areas. Here, one facile and green oxidative etching method induced by UV irradiation is reported to prepare the QDs of MoS/WS in aqueous solution, respectively. A prominent morphology change occurred to the nanosheets of MoS/WS after irradiation and finally they were etched to ultrasmall nanoparticles which were proved to be the QDs.

Note: Wide band amplifier for quartz tuning fork sensors with digitally controlled stray capacitance compensation.

We presented a preamplifier design for quartz tuning fork (QTF) sensors in which the stray capacitance is digitally compensated. In this design, the manually controlled variable capacitor is replaced by a pair of varicap diodes, whose capacitance could be accurately tuned by a bias voltage. A tuning circuit including a single side low power operational amplifier, a digital-to-analog converter, and a microprocessor is also described, and the tuning process can be conveniently carried out on a personal computer.