Haoyan Zang

Bio: Haoyan Zang is an academic researcher from South China University of Technology. The author has contributed to research in topics: Beam (structure) & Optical fiber. The author has an hindex of 2, co-authored 3 publications receiving 120 citations.

Recent advances in non-contact force sensors used for micro/nano manipulation

Abstract: Micro/nano manipulation for both mechanical and biological structures is currently a popular research field. To protect small-scale structures and acquire their mechanical properties, a micro-scale force sensor is needed. This paper focuses on reviewing the research on non-contact micro-force sensor parts that can be integrated in this manipulation system. The content involves the structure, working principle, resolution and sensitivity of different force sensor parts, including electrical and optical force sensors. The electrical force sensors include piezoresistive, piezoelectric, capacitive, electrothermal and strain gauge-based types; while the optical force sensors focus on but are not restricted to the optical fiber-based force sensors and the vision-based sensing systems. All of these sensors are analysed and compared. Electrical force sensors are currently widely used but are restricted by the sensing properties and size; optical force sensors have high sensitivity, small structure and anti-electromagnetic-interference properties, but they are hardly applied in micro/nano manipulation systems for force measurement. As a result, optical force sensors may become the new generation of sensors that can be integrated with micro/nano manipulation systems.

A Novel Force Sensor Based on Optical Fibers Used for Semicircular Flexure Beam Unit

Abstract: In this article, a novel force sensor is designed based on the optical fiber bending loss theory utilizing a structure with periodically corrugated semicircular flexure beam units. The fiber bending loss theory composed of the pure bending loss and the transition loss is related to the curvature radius according to the theoretical analysis. Both the optical working modes and the mechanical properties of the designed sensor are discussed. The output voltage attenuation of different curvature radii is tested and the curvature radius of 6 mm is selected for further experiment. The actual sensing results are acquired using a commercial force sensor. The result shows that the nonlinear errors of the forward and the reverse force applying process are 11.82% and 17.86%, respectively. The sensitivity is 13 mV/N and the precision is 160 mN. The experiment under different temperatures ensures the temperature-insensitive characteristics of the sensor.

Theoretical Analysis of a Novel Force Sensor Based on Optical Fibers Used for Semicircular Flexure Beam Unit

Abstract: In the field of mechanism design, the compliant mechanisms have attracted more and more attention for the unique advantage including no need for assembling, no need for lubrication, no backlash and friction as well as easy fabrication than conventional rigid mechanisms. The periodically corrugated flexure beam units can provide a larger turn angle under the same force, so it is well suited to be designed as a revolute pair. In this paper, the relationship between external force, unit deformation and end point displacement is discussed according to the stiffness matrix method. The structural stress distribution is later discussed by the finite element method (FEM). After the mechanism analysis, a novel force sensor based on optical fibers is designed to detect the mechanical properties of the flexure units. The sensing principle is based on the intensity modulation of curved fibers that the power loss is directly related to the curvature change of a curved fiber. The mechanical-optical mapping relation is established to give the working principle of the sensor. The result shows that this newly designed force sensor has high accuracy and is suitable for the proposed structure.

Development of a Microforce Sensor Based on a Fiber Bragg Grating Used for Micro-/Nanomanipulation

Abstract: In the micro-/nanomanipulation process, the detection of micro-forces is essential not only for sample protection but also for mechanical property tests. In general, optical fiber sensors have excellent sensitivities so they can be used as a kind of new sensing element for microforce sensor design. This article proposes a cantilever-type fiber Bragg grating (FBG)-based microforce sensor with micro-Newton resolution. A complete theoretical model is proposed to establish the mapping between the optical wavelength and the external force, and simulations are also carried out. A series of experiments are performed to evaluate the sensor, which agrees well with the calculation results, showing the sensor has the resolution of 7 $\mu \text{N}$ force in the range of 10 mN. Finally, the calibrated sensor is applied in a micro-/nanomanipulation system to achieve the mechanical property test of the zebrafish embryo. The result fits well with the reference results, proving the microforce sensor has the capability of measuring the mechanical property of the biological sample.

3D-printed sensors: Current progress and future challenges

Abstract: Due to the technological advances, sensors have found a significant role in different aspects of human life. The sensors have been fabricated via various manufacturing processes. Recently, additive manufacturing (AM) has become a common method for fabrication of a wide range of engineering components in many industries. This manufacturing method, commonly known as three-dimensional (3D) printing is based on melting and solidification that leads to production of a component with high dimensional accuracy and smooth surface finish. As precision and elegant techniques are needed in manufacturing of the sensors, AM has been utilized in fabrication of these parts in the last few years. In this study, we summarized and classified applications of different AM methods in manufacturing of sensors. In this context, we briefly reviewed and compared AM techniques and categorized 3D-printed sensors based on their applications. Moreover, fabrication of sensors via AM is explained in details, challenges and future prospect of this manufacturing process are discussed. Investigations on the performed studies proved that higher printing resolution, faster speed and higher efficiency are needed to reach a remarkable advance in the production of 3D-printed sensors. The presented data can be utilized not only for comparison, improvement and optimization of fabrication processes, but also is beneficial for next research in production of highly sensitive sensors.

Additive manufacturing of metallic lattice structures: Unconstrained design, accurate fabrication, fascinated performances, and challenges

Abstract: Lattice structures, which are also known as architected cellular structures, have been applied in various industrial sectors, owing to their fascinated performances, such as low elastic modulus, high stiffness-to-weight ratio, low thermal expansion coefficient, and large specific surface area. The lattice structures fabricated by conventional manufacturing technologies always involve complicated process control, additional assembly steps, or other uncontrollable factors. Furthermore, limited types of unit cells can be used to construct lattice structures when using conventional processes. Fortunately, additive manufacturing technology, based on a layer-by-layer process from computer-aided design models, demonstrates the unique capability and flexibility and provides an ideal platform in manufacturing complex components like lattice structures, resulting in an effective reduction in the processing time to actual application and minimum of material waste. Therefore, additive manufacturing relieves the constraint of structure design and provides accurate fabrication for lattice structures with good quality. This work systematically presents an overview of conventional manufacturing methods and novel additive manufacturing technologies for metallic lattice structures. Afterward, the design, optimization, a variety of properties, and applications of metallic lattice structures produced by additive manufacturing are elaborated. By summarizing state-of-the-art progress of the additively manufactured metallic lattice structures, limitations and future perspectives are also discussed.

Advances in Sensor Technologies in the Era of Smart Factory and Industry 4.0.

Abstract: The evolution of intelligent manufacturing has had a profound and lasting effect on the future of global manufacturing. Industry 4.0 based smart factories merge physical and cyber technologies, making the involved technologies more intricate and accurate; improving the performance, quality, controllability, management, and transparency of manufacturing processes in the era of the internet-of-things (IoT). Advanced low-cost sensor technologies are essential for gathering data and utilizing it for effective performance by manufacturing companies and supply chains. Different types of low power/low cost sensors allow for greatly expanded data collection on different devices across the manufacturing processes. While a lot of research has been carried out with a focus on analyzing the performance, processes, and implementation of smart factories, most firms still lack in-depth insight into the difference between traditional and smart factory systems, as well as the wide set of different sensor technologies associated with Industry 4.0. This paper identifies the different available sensor technologies of Industry 4.0, and identifies the differences between traditional and smart factories. In addition, this paper reviews existing research that has been done on the smart factory; and therefore provides a broad overview of the extant literature on smart factories, summarizes the variations between traditional and smart factories, outlines different types of sensors used in a smart factory, and creates an agenda for future research that encompasses the vigorous evolution of Industry 4.0 based smart factories.