Chengqian Zhang

Zhejiang University | ZJU · Department of Mechanical Engineering

In mass production, injection molding plays a vital role in manufacturing various parts with complex settings. As perfluoroalkoxy alkane (PFA) injection‐molded products are widely used in immersion system, dimensional quality needs more attention. However, there is limited research on the dimension defects of PFA injection‐molded products. This stu...

Manufacturing flexible magnetic-driven actuators with complex structures and magnetic arrangements to achieve diverse functionalities is becoming a popular trend. Among various manufacturing technologies, magnetic-assisted digital light processing (DLP) stands out because it enables precise manufacturing of macro-scale structures and micro-scale di...

The successful exploration of the Mariana Trench, Earth's deepest trench, by soft robots inspired by deep-sea organisms, showcasing the potential of soft robots for extreme deep-sea exploration. However, deep-sea extreme pressure significantly alters the structure and properties of robot materials, affecting their detectability. In this study, to e...

Tactile sensory organs for three-dimensional (3D) force perception are essential for most living organisms and enable them to perform complex and sophisticated tasks to survive and evolve. Magnetic-based tactile sensors have been developed rapidly in recent years due to the exploitability of 3D force decoupling. Here, a method of magnet splicing is...

The advancements in tactile sensor technology have found wide-ranging applications in robotic fields, resulting in remarkable achievements in object manipulation and overall human-machine interactions. However, the widespread availability of high-resolution tactile skins remains limited, due to the challenges of incorporating large-sized, robust se...

Magnetism, a captivating natural phenomenon, has intrigued human curiosity and scientific inquiry for centuries. The ability of certain materials to exert attractive or repulsive forces on other objects without direct physical contact has given rise to a rich history of exploration and discovery. From the enigmatic lodestones of ancient times to th...

Magnetic labels are widely used to aid in the separation and purification of chemical and biological samples. These labels typically consist of superparamagnetic nano- or microspheres, such as Invitrogen’s Dynabeads, which can be covalently attached to a variety of chemical and biological samples. For instance, immunomagnetic separation involves th...

In the study of electromagnetic phenomena, this chapter delves into the domain of magnetic forces, shedding light on the intricate relationship between electric charges, currents, and fields.

Earnshaw's Theorem, formulated by Samuel Earnshaw, serves as a foundational principle within classical mechanics (Simon et al. in Am J Phys 69:702–713, 2001; Geim et al. in Nature 400:323–324, 1999), positing the impossibility of point particles achieving stable equilibrium solely under classical inverse square law forces. This theorem resonates th...

The invention of magnetic levitation detection method brings us a potential density measurement and density-based analysis method. The advantages of standard MagLev device have been proved to be (i) of high accuracy, (ii) of high sensitivity, (iii) applicable to smaller objects, such as droplets and powders, (iv) convenient, and (v) low cost.

A maglev train will be the first thing come up to a man’s imagine when he hears “magnetic levitation”. For it is well known that magnets will be repel each other when their same poles getting close. However, it is impossible to use a single magnet to levitate another magnet. This phenomenon was firstly proved by Earnshaw in 1842 through theoretical...

As one of the inherent characteristics of cell, density is a significant biomarker for the analysis and investigation of multiple cellular events. Density profiles of cell populations are informative data concerning physiological research such as differentiation, live-death assay, aging, immune response, or drug resistance (Durmus et al. in Proc Na...

The magnetic levitation method, characterized by its simplicity, absence of sample magnetization requirements, and convenient operation, has found extensive applications not only in fields such as chemical analysis, biological measurements, and performance characterization but also in the non-contact manipulation of small-sized weakly magnetic mate...

Tactile sensory organs for sensing three‐dimensional (3D) force, such as human skin and fish lateral lines, are indispensable for organisms. With their sensory properties enhanced by layered structures, typical sensory organs can achieve excellent perception as well as protection under frequent mechanical contact. Here, inspired by these layered st...

In chip manufacturing, ultraclean environment is essential during wet processes such as etching, cleaning, and other stages. The fittings used in the process require corrosion resistance, which are made of perfluoroalkoxy alkanes (PFA) by injection molding. Metallic contamination is one of the major impurities for ultraclean products. This study de...

Tactile sensory organs for three-dimensional (3D) force, such as human skin and fish's lateral line, are indispensable for creatures. Empowered by their often layered structure, typical sensory organs can achieve excellent perception as well as protection when facing frequent mechanical contact. Here, inspired by these layered structures, we introd...

Tactile recognition is among the basic survival skills of human beings, and advances in tactile sensor technology have been adopted in various fields, bringing benefits such as outstanding performance in manipulating objects and general human-robot interactions. However, promoting enhanced perception of the existing tactile sensors is limited by th...

The rotation of circular and annular pyrolytic graphite (PG) disks levitating above circular magnet arrays can be used for a novel method of magnetic manipulation, whereas the condition of stable levitation has not been figured out yet. In this article, a method to analyze the diamagnetic forces sustained by levitated PG is proposed to investigate...

High efficiency separation is a significant process of the mechanical recycling to manage the mixed waste plastics. However, most of the extant methods can only deal with binary mixtures. In this paper, a novel automatic and continuous separation method based on magneto-Archimedes levitation is proposed to handle multi-plastics. A theoretical model...

Separation is crucial for recycling heavy metals, however, most of the reported processes focus on separating metals from non-metals. Here we propose a magnetic levitation (MagLev) configuration to separate heavy metals from metallic mixtures. The novel configuration is able to levitate substances with specific densities over 5.00 g/cm3, while the...

Soft actuators are attracting increasing attention for their great potentials in transportation, exploration and clinical treatments, especially the magnetic-driven soft actuators powered by magnetic energy wirelessly. However, the further promotion of complicated three-dimensional magnetic-driven soft actuators with multiple applications is limite...

The research of functional magnetic materials has become a hot topic in the past few years due to their fast, long-range, and precise response in diverse environments. Functional magnetic devices using different magnetic materials and structure designs have been developed and demonstrated good advantages to enable various applications. However, the...

The development of flexible tactile sensors is an emerging field due to their wide applications ranging from human-robot interactions to wearable electronics. This paper proposes a flexible tactile sensor based on the magnetic field for detecting both forces and positions, which exhibited a linear relationship. The direct ink writing technology was...

Magnetic projection, a novel separation method proposed recently, can separate multiple mixed materials in an efficient and low-cost way. Although promising, existing magnetic projection method cannot achieve the automatic feeding of mixed materials, which limits its applications. To address this challenge, ring magnets were used to replace convent...

Magnetic levitation (MagLev) is one of the novel methods that attracts attention from researchers all over the world. It is an accurate and sensitive density testing method that can have applications in the fields of manipulation of particles and cells, chemistry, materials science, and biochemistry, etc. This review mainly focuses on the theory an...

Separating multiple mixed wastes in one step remains a serious challenge because mixtures often have to be separated using a stepwise approach. Bidirectional magnetic projection was thereby developed; the process separates mixed materials simultaneously in a container full of paramagnetic medium by sending the materials from the releasing position...

Magnetic levitation (MagLev) is a promising technology for density-based analysis and manipulation of diamagnetic ob-jects of various physical forms. However, one major drawback is that MagLev can only be performed along the central axis (one- dimensional MagLev), thereby leading to (i) no knowledge about the magnetic field in regions other than th...

In-situ characterization of the molecular orientation during injection molding process remains a great challenge. Failing to penetrate the metallic mold, many conventional methods cannot realize the online measurements during the injection molding process. In comparison, longitudinal ultrasound provides a promising method due to its deep penetratio...

A novel pellet 3D printer was first developed, and its structure was constructed out of three main parts. The material used in this device was polycaprolactone (PCL), which was praised for its good characteristics in the biomanufacturing and chemical industries. Three essential parameters that had important effects on the diameter of the printed fi...

Magnetic levitation (MagLev) is an emerging technology that levitates materials in paramagnetic media, yet standard MagLev devices that are based on two identical square magnets grants limited operational space and applicability. This study focuses on the axial MagLev configuration, which are based on two identical ring magnets. The approach offers...

Ultrasound velocity is a crucial parameter for polymeric parts because it characterizes the mechanical properties and micro structure. In our previous study, we proposed a frequency-domain method for measuring ultrasound velocity via full spectrum analysis (UFSA). In this study, we conducted a series of experiments to compare the accuracy and feasi...

The quality of polymer injection molded parts is definitely related to the molding process. Polymer injection molded parts with different properties differ in density and internal density distribution. This paper proposes a novel evaluation method for polymer injection molded parts through magnetic levitation (MagLev) to detect the differences amon...

A novel magnetic separation method, denoted as ''magnetic projection", was proposed. The method is based on a simple configuration: a container full of paramagnetic medium is placed beside a permanent magnet. Particles of different densities that submerge in the medium are driven by the magnetic force, moving in accordance with different trajectori...

This work proposes an improved magnetic levitation (IML) method for measuring the density of minerals in outdoor exploration by horizontally setting the magnetic levitation device. The measuring characteristic of the method is analyzed and verified by a series of beads with known densities. Combined with the usage of different paramagnetic media, t...

This paper discusses a non-destructive diagnostic method for polymeric samples using magnetic levitation and presents a novel mathematical model to investigate the relevant defect parameters. Magnetic levitation device has two anti-aligned magnets with like poles facing each other and a container of paramagnetic medium in which the polymeric sample...

Magnetic levitation is a recent research hotspot; however, most of the extant configurations use two magnets with like-poles facing each other. This paper proposes a novel magnetic levitation configuration that is based on a single ring magnet, and this configuration opens a wide operational space that enables object manipulation and density-based...

In a magneto-Archimedes levitation device, a polymer can be levitated in a paramagnetic medium, and its equilibrium levitated height is mainly related to its density. Here, a novel density measurement method for polymers via magneto-Archimedes levitation is proposed, in which the relationship between the density and the levitated height is determin...

In magneto-Archimedes levitation, a polymer can be levitated to a balanced position, and its levitation height is mainly related to the density of the polymer. Here, a novel method for measuring the density of polymers based on magneto- Archimedes levitation is proposed. For a designed measurement device, an equation can be fitted by a series of ex...