Wearable Microfluidic Diaphragm Pressure Sensor for Health and Tactile Touch Monitoring

Flexible pressure sensors have many potential applications in wearable electronics, robotics, health monitoring, and more. In particular, liquid-metal-based sensors are especially promising as they can undergo strains of over 200% without failure. However, current liquid-metal-based strain sensors are incapable of resolving small pressure changes in the few kPa range, making them unsuitable for applications such as heart-rate monitoring, which require a much lower pressure detection resolution. In this paper, a microfluidic tactile diaphragm pressure sensor based on embedded Galinstan microchannels (70 µm width × 70 µm height) capable of resolving sub-50 Pa changes in pressure with sub-100 Pa detection limits and a response time of 90 ms is demonstrated. An embedded equivalent Wheatstone bridge circuit makes the most of tangential and radial strain fields, leading to high sensitivities of a 0.0835 kPa^(−1) change in output voltage. The Wheatstone bridge also provides temperature self-compensation, allowing for operation in the range of 20–50 °C. As examples of potential applications, a polydimethylsiloxane (PDMS) wristband with an embedded microfluidic diaphragm pressure sensor capable of real-time pulse monitoring and a PDMS glove with multiple embedded sensors to provide comprehensive tactile feedback of a human hand when touching or holding objects are demonstrated

Wearable Microfluidic Diaphragm Pressure Sensor for Health and Tactile Touch Monitoring

Flexible pressure sensors have many potential applications in wearable electronics, robotics, health monitoring, and more. In particular, liquid-metal-based sensors are especially promising as they can undergo strains of over 200% without failure. However, current liquid-metal-based strain sensors are incapable of resolving small pressure changes in the few kPa range, making them unsuitable for applications such as heart-rate monitoring, which require a much lower pressure detection resolution. In this paper, a microfluidic tactile diaphragm pressure sensor based on embedded Galinstan microchannels (70 µm width × 70 µm height) capable of resolving sub-50 Pa changes in pressure with sub-100 Pa detection limits and a response time of 90 ms is demonstrated. An embedded equivalent Wheatstone bridge circuit makes the most of tangential and radial strain fields, leading to high sensitivities of a 0.0835 kPa^(−1) change in output voltage. The Wheatstone bridge also provides temperature self-compensation, allowing for operation in the range of 20–50 °C. As examples of potential applications, a polydimethylsiloxane (PDMS) wristband with an embedded microfluidic diaphragm pressure sensor capable of real-time pulse monitoring and a PDMS glove with multiple embedded sensors to provide comprehensive tactile feedback of a human hand when touching or holding objects are demonstrated

Ellipse Detection with Applications of Convolutional Neural Network in Industrial Images

Ellipse detection has a very wide range of applications in the field of industrial production, especially in the geometric detection of metallurgical hinge pins. However, the factors in industrial images, such as small object size and incomplete ellipse in the image boundary, bring challenges to ellipse detection, which cannot be solved by existing methods. This paper proposes a method for ellipse detection in industrial images, which utilizes the extended proposal operation to prevent the loss of ellipse rotation angle features during ellipse regression. Moreover, the Gaussian angle distance conforming to the ellipse axioms is adopted and combined with smooth L1 loss as the ellipse regression loss function to enhance the prediction accuracy of the ellipse rotation angle. The effectiveness of the proposed method is demonstrated on the hinge pins dataset, with experiment results showing an AP* of 80.93% and indicating superior detection performance compared to other methods. It is thus suitable for engineering applications and can provide visual guidance for the precise measurement of ellipse-like mechanical parts

BN-Heterocycles Bearing Two BN Units: Influence of the Linker and the Location of BN Units on Electronic Properties and Photoreactivity

Four diboron BN-heterocycles bearing two BN units have been synthesized via double lithiation/borylation with the aim to examine their thermal and photoelimination properties. In two of the BN-heterocycles, <b>(BN)</b>_<b>2</b><b>-1</b> and <b>(BN)</b>_<b>2</b><b>-4</b>, the BN units share the central linker unit, while the other two BN-heterocycles <b>(BN)</b>_<b>2</b><b>-2</b> and <b>(BN)</b>_<b>2</b><b>-3</b> are isomers with a benzene ring in the middle of the backbone separating the two chelate units. Only compound <b>(BN)</b>_<b>2</b><b>-3</b> can thermally and photochemically undergo complete double elimination producing green fluorescent <b>(BN)</b>_<b>2</b><b>-3a</b> due to the highly crowded boron centers. <b>(BN)</b>_<b>2</b><b>-2</b> can partially convert (∼56%) to <b>(BN)</b>_<b>2</b><b>-2a</b> under 350 nm UV irradiation. <b>(BN)</b>_<b>2</b><b>-1</b> and <b>(BN)</b>_<b>2</b><b>-4</b> are either inactive or unstable toward photolysis. The molecular structures and electronic properties of these (BN)₂-heterocycles have been investigated experimentally as well as computationally using TD-DFT to further elucidate the origin of differences in optical and electronic properties