Correction: Abazari, A.M., et al. Modelling the Size Effects on the Mechanical Properties of Micro/Nano Structures. Sensors 2015, 15, 28543-28562.

The authors wish to make the following correction to this paper [1]: The article type should be changed from "Review" into "Article".[...].

Modelling the Size Effects on the Mechanical Properties of Micro/Nano Structures.

Experiments on micro- and nano-mechanical systems (M/NEMS) have shown that their behavior under bending loads departs in many cases from the classical predictions using Euler-Bernoulli theory and Hooke's law. This anomalous response has usually been seen as a dependence of the material properties on the size of the structure, in particular thickness. A theoretical model that allows for quantitative understanding and prediction of this size effect is important for the design of M/NEMS. In this paper, we summarize and analyze the five theories that can be found in the literature: Grain Boundary Theory (GBT), Surface Stress Theory (SST), Residual Stress Theory (RST), Couple Stress Theory (CST) and Surface Elasticity Theory (SET). By comparing these theories with experimental data we propose a simplified model combination of CST and SET that properly fits all considered cases, therefore delivering a simple (two parameters) model that can be used to predict the mechanical properties at the nanoscale.

Enhancing flexibility and strength-to-weight ratio of polymeric stents: A new variable-thickness design approach.

This paper presents a new design strategy to improve the flexibility and strength-to-weight ratio of polymeric stents. The proposed design introduces a variable-thickness (VT) stent that outperforms conventional polymeric stents with constant thickness (CT). While polymeric stents offer benefits like flexibility and bioabsorption, their mechanical strength is lower compared to metal stents. To address this limitation, thicker polymer stents are used, compromising flexibility and clinical performance. Leveraging advancements in 3D printing, a new design approach is introduced in this study and is manufactured by the Liquid Crystal Display (LCD) 3D printing method and PLA resin. The mechanical performance of CT and VT stents is compared using the Finite Element Method (FEM), validated by experimental tests. Results demonstrate that the VT stent offers significant improvements compared to a CT stent in bending stiffness (over 20%), reduced plastic strain distribution of expansion (over 26%), and increased radial strength (over 10%). This research showcases the potential of the VT stent design to enhance clinical outcomes and patient care.

Calculating and analyzing time delay in zigzag graphene nanoscrolls based complementary metal-oxide-semiconductors.

Graphene Nano Scrolls (GNSs) and Zigzag graphene nanoscrolls (ZGNSs) are semi-one-dimensional materials with exceptional electrical and optical properties, making them attractive to be used in nanoelectronics and complementary metal-oxide-semiconductor (CMOS) technology. With in CMOS device technology, time delay is a crucial issue in the design and implementation of CMOS based ZGNSs. Current paper focus is on ZGNSs application in the channel area of metal-oxide-semiconductor field-effect transistors (MOSFETs) in CMOS technology. We studied analytically, the importance of different parameters on time delay reduction, resulting in faster switching and higher frequency in integrated circuits (ICs). The results of this research demonstrates that, the ZGNS-based CMOS proves considerable variations in the current due to the geometrical parameters, such as chirality number, channel length, and nanoscroll length which can be engineered to produce faster ICs.

Investigation of the stent induced deformation on hemodynamic of internal carotid aneurysms by computational fluid dynamics.

Application of the stent for treatment of the internal carotid artery (ICA) aneurysms has been extensively increased in recent decades. In the present work, stent-induced deformations of the parent vessel of ICA aneurysms are fully investigated. This study tries to visualize blood stream and calculated hemodynamic factors inside the four ICA aneurysms after deformations of parent vessel. For the simulation of the non-Newtonian blood stream, computational fluid dynamic is applied with one-way Fluid-Solid interaction (FSI) approach. Four ICA aneurysms with different ostium sizes and neck vessel angle are selected for this investigation. Wall shear stress on wall of aneurysm is analyzed in two angles of deformation due to application of the stent. Blood flow investigation shows that the deformation of the aneurysm limited blood entrance to the sac region and this decreases the blood velocity and consequently oscillatory shear index (OSI) on the sac wall. It is also observed that the stent-induced deformation is more effective on those cases with extraordinary OSI values on aneurysm wall.

Avoiding transduction-induced heating in suspended microchannel resonators using piezoelectricity.

Calorimetry of single biological entities remains elusive. Suspended microchannel resonators (SMRs) offer excellent performance for real-time detection of various analytes and could hold the key to unlocking pico-calorimetry experiments. However, the typical readout techniques for SMRs are optical-based, and significant heat is dissipated in the sensor, altering the measurement and worsening the frequency noise. In this manuscript, we demonstrate for the first time full on-chip piezoelectric transduction of SMRs on which we focus a laser Doppler vibrometer to analyze its effect. We demonstrate that suddenly applying the laser to a water-filled SMR causes a resonance frequency shift, which we attribute to a local increase in temperature. When the procedure is repeated at increasing flow rates, the resonance frequency shift diminishes, indicating that convection plays an important role in cooling down the device and dissipating the heat induced by the laser. We also show that the frequency stability of the device is degraded by the laser source. In comparison to an optical readout scheme, a low-dissipative transduction method such as piezoelectricity shows greater potential to capture the thermal properties of single entities.