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The effect of viscosity on the performance of disk-shaped electromechanical resonators has been studied and investigated in the past. The vibration frequency of a disk-shaped resonator changes according to the viscosity of the liquid which the resonator is in contact with. Therefore, the purpose of this paper is based on design a sensor for measuring the viscosity of liquids using a disk-shaped electromechanical resonator. The viscosity of liquids is of interest to researchers in industry and medicine.

In this paper, a viscosity sensor for liquids is proposed, which is designed based on a disk-shaped electromechanical resonator. In this proposed sensor, two comb drives are used as electrostatic actuators to stimulate the resonator. Also, two other comb drives are used as electrostatic sensors to monitor the frequency changes of the proposed resonator. The resonance frequency of the resonator in response to different fluids under test varies according to their viscosity.

After calibration of the proposed sensor by nonlinear weights, the viscosity of some liquids are calculated using this sensor and results confirm its accuracy according to the liquids real viscosity.

The design of the proposed sensor and its simulated performance are reported. Also, the viscosity of several different liquids are evaluated with simulations of the proposed sensor and presented.

The purpose of this paper is to provide an introduction to micro-electromechanical systems (MEMS) sensors and their commercialisation and to consider a number of recent applications, markets and product developments.

Following an introduction and a brief historical background to MEMS sensors and their commercialisation, the paper describes a selection of recent applications, with an emphasis on high volume uses. Various market figures are included to place these applications in a commercial context. Sensors for both physical variables and gases are considered.

The paper shows that MEMS sensor applications continue to grow in the automotive, consumer electronics and other industries, which consume many millions of sensors annually. New product developments reflect the requirement for smaller and lower-cost sensors with enhanced performance and greater functionality. Markets for physical sensors dominate but MEMS technology is making progressive inroads in the gas sensing field.

This article provides a timely review of a selection of recent MEMS sensor applications, markets and product developments.

The purpose of this study is to investigate the effect of internal and external factors on the accuracy and consistency of the data provided by mobile-embedded micro-electromechanical system (MEMS) pressure sensors based on smartphones currently in use.

For this purpose, sensor type and smartphone model have been regarded as internal factors, whereas temperature, location and usage habits have been considered as external factors. These factors have been investigated by examining data sets provided by sensors from 14 different smartphones. In this context, internal factors have been analyzed by implementing accuracy assessment processes for three different smartphone models, whereas external factors have been evaluated by analyzing the line charts which present timely pressure changes.

The study outlined that the sensor data at different sources have different characteristics due to the affecting parameters. Even if the pressure sensors are used under similar circumstances, data of these sensors have inconsistencies because of the sensor drift originated by internal factors. This study concluded that it was not applicable to provide a common correction coefficient for pressure sensor data of each smartphone model. Therefore, relative data (pressure differences) should be taken into consideration rather than absolute data (pressure values) when developing mobile applications using sensor data.

Results of this study can be used as the guideline for developing mobile applications using MEMS pressure sensors. One of the main finding of this paper is promoting the use of relative data (pressure differences) rather than absolute data (pressure values) when developing mobile applications using smartphone-embedded sensor data. This significant result was proved by examinations applied with in the study and can be applied by future research studies.

Existing studies mostly evaluate the use of MEMS pressure sensor data obtained from limited number of smartphone models. As each smartphone model has a specific technology, factors affecting the sensor performances should be identified and analyzed precisely in terms of smartphone models for providing extensive results. In this study, five smartphone models were used fractionally. In this context, they were used for examining the common effects of the factors, and detailed accuracy assessments were applied by using two high-tech smartphones in the market.

To give a background to the automotive sensor industry and consider recent developments in sensors used in vehicle safety systems.

This paper describes the early development of the automotive sensor industry and gives examples of present‐day applications. It subsequently discusses development in advanced vehicle safety systems.

The advent of cost‐effective electronics in 1970 led to the development of numerous automotive systems such as electronic engine management which use a diversity of sensors. Since, the 1990s, safety has emerged as a major consideration and features such as traction control, ABS, stability control systems and air bags have been applied across a wide sector of the industry. New active safety systems which respond to passenger weight and position, as well as collision avoidance systems which can sense the vehicle's external environment are being developed and applied widely. These are fuelling the automotive sensor market which is forecast to reach 2.24 billion units per annum by 2010.Safety system integration is a major theme of present developments.

This paper shows that customer demands for enhanced safety have driven the development and rapid adoption of advanced vehicle safety systems. This has boosted the markets for automotive sensors.

At present, piezoelectric impedance technology has been used in the study of wood damage monitoring. However, little effort has been made in the research on the application of piezoelectric impedance system to monitor the change of wood moisture content (MC). The monitoring method of wood MC is used by piezoelectric impedance technique in this study.

One piezoceramic transducer is bonded to the surface of wood specimens. The MC of the wood specimens increases gradually from 0% to 60% with 10% increments; the mechanical impedance of the wood specimen will change, and the change in the mechanical impedance of the structure is reflected by monitoring the change in the electrical impedance of lead zirconate titanate. Therefore, this paper investigates the relationship between wood MC change and piezoelectric impedance change to verify the feasibility of the piezoelectric impedance method for monitoring wood MC change.

The experiment verified that the real part of impedance of the wood increased with the increase of wood MC. Besides, the damage index root mean square deviation is introduced to quantify the damage degree of wood under different MC. At the same time, the feasibility and validity of this experiment were verified from the side by finite element simulation. Finally, MC monitoring by piezoelectric impedance technique is feasible.

To the best of the authors’ knowledge, this work is the first to apply piezoelectric ceramics to the monitoring of wood MC, which provides a theoretical basis for the follow-up study of a wide range of wood components and even wood structure MC changes.

The purpose of this paper is to present the design, analysis, fabrication, and assembly of four tooth annular microfabricated tactile sensors integrated with the upper and lower jaws of an endoscopic surgical grasper tool, in order to determine the properties and particularly the compliance of the biological tissues during minimally invasive surgery.

A viscoelastic Kelvin model is employed for tissue characterization. A comprehensive closed form and finite element analysis has been carried out to express the relationship between the force ratio, compliance, and the equivalent viscous damping of the tissue. The designed sensor uses a polyvinyledene fluoride film as its sensing element. The sensor consists of arrays of rigid and compliant elements which are mounted on the tip of an endoscopic surgical grasper tool. Relative force between adjacent parts of the contact object is used to measure the viscoelastic properties.

The tactile sensor is able to characterize different viscoelastic properties of tissues. The experiments validate analytical and finite elements results.

The sensor is designed to integrate with the actual endoscopic tools to measure the softness of tissues.

A novel sensor‐tissue model is presented to characterize the variety of biological tissues.

The purpose of this paper is to develop a highly miniaturized wireless inertial sensor system based on a novel 3D packaging technique using a flexible printed circuit (FPC). The device is very suitable for wearable applications in which small size and lightweight are required such as body area network, medical, sports and entertainment applications.

Modern wireless inertial measurement units are typically implemented on a rigid 2D printed circuit board (PCB). The design concept presented here is based around the use of a novel planar, six‐faceted, crucifix or cross‐shaped FPC instead of a rigid PCB. A number of specific functional blocks (such as microelectromechanical systems gyroscope and accelerometer sensors, microcontroller (MCU), radio transceiver, antenna, etc.) are first assigned to each of the six faces which are each 1 cm² in area. The FPC cross is then developed into a 1 cm³, 3D configuration by folding the cross at each of five bend planes. The result is a low‐volume and lightweight, 1 cm³ wireless inertial sensor that can sense and send motion sensed data wirelessly to a base station. The wireless sensor device has been designed for low power operation both at the hardware and software levels. At the base station side, a radio receiver is connected to another MCU unit, which sends received data to a personal computer (PC) and graphical user interface. The industrial, scientific and medical band (2.45 GHz) is used to achieve half duplex communication between the two sides.

A complete wireless sensor system has been realized in a 3D cube form factor using an FPC. The packaging technique employed during the work is shown to be efficient in fabricating the final cubic system and resulted in a significant saving in the final size and weight of the system. A number of design issues are identified regarding the use of FPC for implementing the 3D structure and the chosen solutions are shown to be successful in dealing with these issues.

Currently, a limitation of the system is the need for an external battery to power the sensor system. A second phase of development would be required to investigate the possibility of the integration of a battery and charging system within the cube structure. In addition, the use of flexible substrate imposes a number of restrictions in terms of the ease of manufacturability of the final system due to the requirement of the required folding step.

The small size and weight of the developed system is found to be extremely useful in different deployments. It would be useful to further explore the system performance in different application scenarios such as wearable motion tracking applications. In terms of manufacturability, component placement needs to be carefully considered, ensuring that there is sufficient distance between the components, bend planes and board edges and this leads to a slightly reduced usable area on the printed circuit.

This paper provides a novel and useful method for realizing a wireless inertial sensor system in a 3D package. The value of the chosen approach is that a significant reduction in the required system volume is achieved. In particular, a 78.5 per cent saving in volume is obtained in decreasing the module size from a 25 to a 15 mm³ size.

The utilization of artificial intelligence (AI) in the solution of many problems encountered in healthcare in recent years is rapidly becoming widespread. Understanding of the use and importance of efficiency, security and accessible healthcare to everyone and providing value-based services for healthcare decision-makers is essential. The special uses of machine learning, natural language processing and smart voice assistants, which have developed as sub-branches of AI, for healthcare services, the contributions of these techniques to the digital transformation of healthcare services and how all these will help decision-making processes in healthcare services, will be discussed in this chapter. And also, FDA-approved algorithms that are a kind of AI tool will be explained.

To describe the historical development of micro‐electromechanical system (MEMS) sensor technology, to consider its current use in physical, gas and chemical sensing and to identify and discuss future technological trends and directions.

This paper identifies the early research which led to the development of MEMS sensors. It considers subsequent applications of MEMS to physical, gas and chemical sensing and discusses recent technological innovations.

This paper illustrates the greatly differing impacts exerted on physical, gas and chemical sensing by MEMS technology. More recent developments are discussed which suggest strong market prospects for MEMS devices with analytical capabilities such as microspectrometers, micro‐GCs, microfluidics, lab‐on‐a‐chip and BioMEMS. This view is supported by various market data and forecasts.

This paper provides a technical and commercial insight into the applications of MEMS technology to physical and molecular sensors from the 1960s to the present day. It also identifies high growth areas for innovative developments in the technology.

Detection of low-frequency pressures such as heart rate in the range of 1 Hz is one of the applications of low-frequency resonator. In this paper, the structure of the resonator is in the form of a plate, whose mathematical model has been extracted according to past works and is reported.

This paper presents an electromechanical microresonator that can be used as an ultra-low-frequency pressure sensor. It is very important to choose the right material for the sensors to have the optimal conditions. In this work, by proposing the innovative use of polytetrafluoroethylene material with low stiffness coefficient, the necessary conditions are provided to reduce the vibration frequency of the resonator.

The proposed design is simulated with the help of COMSOL, and its results are compared with the results of the mathematical model, which are very close to each other. Therefore, by inferring the results, the authors can rely on accurate simulations and finalize the similar designs with full confidence before fabrication.

There are important advantages regarding the geometry of the proposed design structure that is the possibility of detecting a pressure of 1 Pa only with voltages less than 2 V. On the other hand, the pull-in effect causes very low frequencies to be achieved in detection with the help of the proposed resonator. Also, the linear and nonlinear behavior of the resonator by applying different pressures has been studied and reported to find the appropriate operating range of the resonator and its limitations.