Qingchuan Zhang

University of Science and Technology of China | USTC · Department of Modern Mechanics

Cancer is a profound danger to our life and health. The classification and related studies of epithelial and mesenchymal phenotypes of cancer cells are key scientific questions in cancer research. Here, we investigated cancer cell colonies from a mechanical perspective and developed an assay for classifying epithelial/mesenchymal cancer cell coloni...

Optical tweezers exert a strong trapping force on cells, making it crucial to analyze the movement of trapped cells. The rotation of cells plays a significant role in their swimming patterns, such as in sperm cells. We proposed a fast deep-learning-based method that can automatically determine the projection orientation of ellipsoidal-like cells wi...

Morphology and motility are essential criteria for assessing sperm viability. However, the human sperm head is small (∼3–4 μm) and requires a relatively high-magnification microscope objective, while the sperm flagella (∼45 μm) are poorly visible with complex 3D properties. Microscopic dynamic observation of intact sperm in 3D is challenging. Conve...

To improve the detection capability of satellite-based synthetic aperture radar, a large antenna array with a length scale of 100 meters is urgently needed. However, the structural deformation of the large antenna leads to phase errors, which will significantly reduce the antenna gain; hence, real-time and high-precision profile measurements of the...

Early Diagnosis of Cancers In article 2205445, Shangquan Wu, Qingchuan Zhang, and co‐workers develop an ultra‐sensitive nanomechanical sensor, which uses a magnetic‐driven microcantilever array to selectively detect oncogenic exosomes. The magnetic force produces a far greater deflection of microcantilever than that produced by the intermolecular i...

Owning to its flexibility, high temperature resistance, and freedom from electromagnetic interference, coherent optical fiber bundle (COFB) is widely used in special imaging applications. However, limited by the manufacturing process, the fiber arrangement of COFB is prone to misalignment, resulting in imaging distortions that are not easily correc...

The security and convenience of high-speed railways depend on the high reliability and high stability of ballastless tracks. To ensure track regularity, it is necessary to measure the height deviation of each rail bearing platform before laying the steel rail. By adjusting the fastening system, the rail could reach the design height and be at the s...

Exosomes are a class of nanoscale vesicles secreted by cells, which contain abundant information closely related to parental cells. The ultrasensitive detection of cancer‐derived exosomes is highly significant for early non‐invasive diagnosis of cancer. Here, an ultrasensitive nanomechanical sensor is reported, which uses a magnetic‐driven microcan...

Unlabelled: Ultrasensitive molecular detection and quantization are crucial for many applications including clinical diagnostics, functional proteomics, and drug discovery; however, conventional biochemical sensors cannot satisfy the stringent requirements, and this has resulted in a long-standing dilemma regarding sensitivity improvement. To this...

Traction force microscopy (TFM) is one of the most successful and broadly-used force probing technologies to quantify the mechanical forces in living cells. The displacement recovery of the fluorescent beads within the gel substrate, which serve as the fiducial markers, is one of the key processes. The traditional methods of extracting beads displa...

The division-of-focal-plane (DoFP) polarimeter can quickly and effectively obtain the polarization information of light in real time, where Stokes parameter reconstruction is a critical issue. Many reconstruction methods have been proposed to address this; however, their performance tends to degrade in the presence of noise. Thus, it is significant...

The massive global spread of the COVID-19 pandemic makes the development of more effective and easily popularized assays critical. Here, we developed an ultrasensitive nanomechanical method based on microcantilever array and peptide nucleic acid (PNA) for the detection of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) RNA. The method...

The beginning of a mammalian life commences with a fertilized oocyte. The study of oocytes is certainly one of the most intriguing scientific questions of our time. Herein, we studied oocytes from a mechanical perspective and characterized the typical life activities of oocytes by nanomechanical vibrations. During the development of oocytes from th...

The three-dimensional digital image correlation (3D-DIC) method featuring two synchronized cameras has been widely used in the field of experimental mechanics to measure full-field 3D shape and deformation. However, the requirement of two synchronized cameras often limits the application of the regular 3D-DIC method. This study proposes a single-ca...

As cells have the capacity to respond to their mechanical environment, cellular biological behaviors can be regulated by the stiffness of extracellular matrix. Moreover, biological processes are dynamic and accompanied by matrix stiffening. Herein, we developed a stiffening cell culture platform based on polyacrylamide-Fe3O4 magnetic nanocomposite...

We design and fabricate a novel lithium-ion battery system based on direct contact liquid cooling to fulfill the application requirement for the high-safety and long-range of electric vehicles. By the immersion in the flowing silicone oil to achieve the highly efficient heat exchange, the NCM811 cells can be grouped without gap, and thereby the bat...

We propose a calibration method for stereo camera with a large field of view (FOV) using zoom lenses. We adopted Magill’s formula, using intrinsic parameters with small object distances to calculate intrinsic parameters with large object distances. We employed a regular sized calibration board to calibrate extrinsic parameters in the small FOV, usi...

Generating digital speckle image and its corresponding deformed image is the basis of digital image correlation research. At present, however, it still lacks a powerful, easy-to-use, and user-friendly professional software concerning generation and assessment of digital speckle pattern. Researchers have to reimplement the generation algorithms in l...

Early cancer diagnosis requires ultrasensitive detection of tumor markers in blood. To this end, we develop a novel microcantilever immunosensor using nanobodies (Nbs) as receptors. As the smallest antibody (Ab) entity comprising an intact antigen-binding site, Nbs achieve dense receptor layers and short distances between antigen-binding regions an...

Digital volume correlation (DVC) method is extensively used for the internal displacement measurement. In biomechanical experiments, fluorescent beads are used, instead of traditional speckles (or microstructure of materials), as the information feature of the volume image for DVC algorithm. The traditional experimental method and DVC algorithm, to...

The mechanical force between cells and the extracellular microenvironment is crucial to many physiological processes such as cancer metastasis and stem cell differentiation. Mitosis plays an essential role in all these processes and thus an in-depth understanding of forces during mitosis gains insight into disease diagnosis and disease treatment. H...

The generation of digital speckle image and its corresponding deformed image is the basis of study of digital image correlation. At present, however, there is still no powerful, easy-to-use, and user-friendly software for digial speckle generation and assessment. Researchers must reimplement the generation algorithms in literatures, which is time-c...

Okadaic acid (OA) is widely present in seafood and consuming OA contaminated seafood can cause carcinogenic or teratogenic effects. Therefore, developing ultra-sensitive and rapid detection methods for OA is crucial. Here, an aptamer-based microcantilever array sensor was developed for ultra-sensitive and rapid detection of OA. OA aptamers were imm...

The initial value estimation for seed point is the first step in digital image correlation calculation. Among the existing algorithms, the Fourier–Mellin transform-based cross correlation (FMT-CC) algorithm is one of the most efficient and robust owing to its rotation- and scale-invariance. However, when the displacement is large (more than a hundr...

Reducing the charging time for electric vehicles (EVs) is considered as a crucial factor to promote consumer interest and improve the competitiveness of EVs in the automotive market. Therefore, the investigation of fast charging protocol becomes increasingly important. In this work, a novel self‐adaptive fast charging protocol for cylindrical lithi...

For subset-based digital image correlation, the random error of second-order shape function roughly doubles that of first-order shape function, termed doubled random error phenomenon. In this work, we suggest that the fundamental cause of this phenomenon is the uniformity and isotropy of speckle pattern. Specially, we prove that the ratio of random...

Division-of-focal-plane modulation is a powerful technique for real-time polarization imaging. This technique, however, suffers from the non-uniformity of the performance of linear polarization filters and photodetectors. We study the Stokes parameters reconstruction from the division-of-focal-plane modulation in the presence of the non-uniformity....

As known to all, optical tweezers depend intensely on trapping laser power. Therefore, the ability to separately regulate trapping power for each optical trap under a multi-object manipulation task empowers researchers with more flexibility and possibilities. Here, we introduce a simple strategy using complementary random binary phase design to ach...

Optical tweezers are constantly evolving micromanipulation tools that can provide piconewton force measurement accuracy and greatly promote the development of bioscience at the single-molecule scale. Consequently, there is an urgent need to characterize the force field generated by optical tweezers in an accurate, cost-effective, and rapid manner....

The macroscopically localized deformation behaviors of Ni–Co-based superalloys with different γ′ precipitate content were investigated at 500 °C and 1 × 10⁻⁴ s⁻¹ via an in situ method namely, digital image correlation (DIC). The DIC results showed that the serrated flow of the stress–strain curves was accompanied by localized deformation of the spe...

In nuclear fusion reactors, the key structural component (i.e., the plasma-facing component) undergoes high heat flux cyclic loading. To ensure the safety of fusion reactors, an experimental study on the temperature-induced creep of stainless steel under heat flux cyclic loading was performed in the present work. The strains were measured using a s...

The performance of digital image correlation is closely associated with the quality of speckle pattern. In this paper, the performance of digital speckle pattern is analyzed theoretically concerning four critical factors: uniqueness, accuracy, precision, and spatial resolution. Pattern uniqueness could be characterized by secondary autocorrelation...

Chirality is an essential consideration in the field of life sciences and pharmaceutical industry because most biomolecules and pharmaceuticals are chiral, and optical rotation measurement is a simple and efficient means for identification, purity test and content detection of chiral materials. However, there are some drawbacks in existing methods,...

A strategy called random subset is presented to reduce systematic error in digital image correlation caused by intensity interpolation. In classical digital image correlation techniques, the subset points fall at integer locations; by contrast, the proposed random subset strategy imposes random offsets on the conventional locations, and consequentl...

Digital image correlation is a widely used optical metrology for shape, motion, and deformation measurement. Although a number of studies have been carried out on the measurement errors of digital image correlation, the spatial uncertainty of the measurement errors, which stems from the randomness of speckle patterns, is seldom researched. In this...

Cyanotoxins, produced by cyanobacteria, are a series of widely present toxins frequently found in freshwater during algal blooms. They are extremely hazardous and persistent, which makes them a seriousthreat to human and animal health. In this paper, we developed an aptamer-based microcantilever arraysensor to detect microcystin-leucine-arginine (M...

Profenofos, a highly poisonous organophosphorus pesticide, has been widely used in agricultural production. These pesticide residues have seriously influenced food security and threatened human health, and new methods with high sensitivity are greatly needed to detect profenofos. Here, we developed an aptamer-based microcantilever-array sensor oper...

In the measurement of plate specimens, traditional two-dimensional (2D) digital image correlation (DIC) is challenged by two aspects: (1) the slant optical axis (misalignment of the optical camera axis and the object surface) and (2) out-of-plane motions (including translations and rotations) of the specimens. There are measurement errors in the re...

It is believed that the classic forward additive Newton–Raphson (FA-NR) algorithm and the recently introduced inverse compositional Gauss–Newton (IC-GN) algorithm give rise to roughly equal interpolation bias. Questioning the correctness of this statement, this paper presents a thorough analysis of interpolation bias for the IC-GN algorithm. A theo...

Infertility, whether of male or female origin, is a critical challenge facing the low birth rate and aging population throughout the world, and semen analysis is a cornerstone of the diagnostic evaluation of the male contribution to infertility. This means that tools which can characterize sperm properties in an effective manner are very much neede...

Image registration is the key technique of optical metrologies such as digital image correlation (DIC), particle image velocimetry (PIV), and speckle metrology. Its performance depends critically on the quality of image pattern, and thus pattern optimization attracts extensive attention. In this article, a statistical model is built to optimize spe...

Three dimensional-digital image correlation (3D-DIC) is a widely used optical metrology in the experimental mechanics community because of its reliability, practicality, and flexibility. Although the precision of digital image correlation (DIC) has been thoroughly studied theoretically and numerically, verification experiments have seldom been perf...

Pulse diagnosis is an essential part in four basic diagnostic methods (inspection, listening, inquiring and palpation) in traditional Chinese medicine, which depends on longtime training and rich experience, so computerized pulse acquisition has been proposed and studied to ensure the objectivity. To imitate the process that doctors using three fin...

Due to its convenience of operation, the camera calibration algorithm, which is based on the plane template, is widely used in image measurement, computer vision and other fields. How to select a suitable distortion model is always a problem to be solved. Therefore, there is an urgent need for an experimental evaluation of the accuracy of camera di...

Array sensing is increasingly important in the development of microcantilever (MC) sensors, and response consistency is the foundation for MC array sensing. In the present work, we investigated the response consistency of MC array sensing. The responses of two types of commercially available MC arrays were studied under conditions of temperature ch...

We developed a microcantilever array biosensor instrument based on optical readout from a microcantilever array in fluid environment. The microcantilever signals were read out sequentially by laser beams emitted from eight optical fibers. The optical fibers were coupled to lasers, while the other ends of the fibers were embedded in eight V-grooves...

The Protein-Le Chatelier (PLC) effects are investigated by using digital image correlation at a constant applied strain rate of 5.00×10⁻³ s⁻¹ and room temperature in Al-Mg alloys with Mg content values (wt.%) of 2.30, 4.57, 6.10 and 6.91 respectively in this study. Both the yield strength and the ultimate strength increase with increasing Mg conten...

The primary objective of this proceeding is to properly assess the quality of speckle patterns utilized in digital image correlation (DIC). Since a good pattern should associate with a small measurement error, the overall error can be used to assess the quality of a speckle pattern. The overall error consists of interpolation bias, noise-induced bi...

The traditional two-dimensional (2D) digital image correlation (DIC) method often leads to results without enough accuracy due to the out-of-plane motions of the specimens in the deformation measurements of plate specimens. To remove the effects of the out-of-plane motions, a compensation method for the 2D DIC method has been developed. The compens...

There are displacement systematic errors due to undermatched shape functions and strain systematic errors due to undermatched surface fitting functions using the digital image correlation (DIC) method. The measured displacement and strain results are heavily affected by the calculation parameters (such as the subset size, the grid step, and the str...

When measuring plate specimen deformations, traditional two-dimensional (2D) digital image correlation (DIC) often leads to insufficiently accurate results due to out-of-plane motion of the specimen during the measurement. To remove the effects of out-of-plane motion, a compensation method for 2D DIC has been developed by researchers. The method ma...

A cantilever array sensor platform was developed based on the optical lever method, and the cantilever array chip was also fabricated to introduce its applications on biochemical detection. Optical fibers coupled to lasers were used as the scanning light source. This sensor system had good stability, and the noise of the detection signal was about...

This paper presents a system for positioning markers and tracking the pose of a rigid object with 6 degrees of freedom in real-time using 3D digital image correlation, with two examples for medical imaging applications. Traditional DIC method was improved to meet the requirements of the real-time by simplifying the computations of integral pixel se...

In this paper, we numerically studied the intensity patterns and screw phases of an embedded optical vortex in an Airy beam generated by a 3/2 phase pattern imposed on a spatial light modulator. It is found that the optical vortex and the Airy beam’s main lobe approach each other during propagation, which means the energy of the Airy beam’s intensi...

The measurement accuracy using the digital image correlation (DIC) method in local deformations such as the Portevin–Le Chatelier bands, the deformations near the gap, and the crack tips has raised a major concern. The measured displacement and strain results are heavily affected by the calculation parameters (such as the subset size, the grid step...

Cancer is a serious threat to human health. Although numerous anti-cancer drugs are available clinically, many have shown toxic side effects due to poor tumor-selectivity, and reduced effectiveness due to cancers rapid development of resistance to treatment. The development of new highly efficient and practical methods to quantify cell viability an...

Although γ′ precipitates enhance the strength of Ni-based superalloys, they can also promote an undesirable phenomenon called the Portevin–Le Chatelier (PLC) effect. Alloys designed and fabricated with various γ′ contents were subjected to uniaxial tensile tests at different temperatures (523–923 K) and strain rates (1 × 10⁻⁴–3 × 10⁻³ s⁻¹). It was...

For the first time ever, a thickness dependence of the Lüders effect in an Al-based alloy is demonstrated. A three-dimensional digital image correlation method was used to gain insight into the Lüders band velocity and the Lüders strain. The results revealed that both the strain and velocity depend on the specimen thickness. The strain increases, w...

The Portevin–Le Chatelier (PLC) effect in Al–2.30wt%Mg, Al–4.57wt%Mg and Al–6.91wt%Mg alloys has been investigated at various applied strain rates at room temperature in this study. Three-dimensionaldigital image correlation (3D-DIC) technique was applied to obtaining the further insight into the spa-tiotemporal characteristics, in particular the i...

In view of its high precision and high efficiency, three-dimensional digital image correlation (3D-DIC) is widely used to accurately measure full-field deformation. A spatiotemporal experimental study using 3D-DIC to explore the Portevin–Le Chatelier (PLC) deformational behavior, provides a new insight into the whole 3D deformation field, including...

Recently, accelerating beam is becoming a hotspot in optics research. In this paper, we studied the evolving phases of accelerating generalized polygon beams (AGPBs) and proposed a novel method to generate this beam family. An important discovery has been made about reconstructing AGPBs only by evolving low-frequency phases in high power region, wh...

An optical readout focal plane array (FPA) usually has a differently tilted reflector/absorber at the initial state due to the micromachining technique. The angular deviation of the reflector/absorber has a strong impact on the optical sensitivity non-uniformity, which is a key factor which affects the imaging uniformity. In this study, a theoretic...

The mechanism of the critical strain of serrated yielding is studied via tension tests at various strain rates. Before the critical strain, it is deduced that dislocations are not pinned at high strain rates, and dislocations at low strain rates are pinned but cannot escape. The critical strain depends on the first pinning process at high strain ra...

In digital image correlation (DIC), the noise-induced bias is significant if the noise level is high or the contrast of the image is low. However, existing methods for the estimation of the noise-induced bias are merely applicable to traditional interpolation methods such as linear and cubic interpolation, but are not applicable to generalized inte...

A two-dimensional Monte Carlo dynamic model has been developed to simulate the interaction between mobile dislocations and solute atoms. When there was a single dislocation with a constant stress rate, the dislocation was pinned under low stress rate conditions, moved continuously under high stress rate conditions, and moved intermittently at an in...

The special spiral phase structure of an optical vortex leads to an intriguing study in modern singular optics. This paper proposes a real-time phase measurement method of vortex beam based on pixelated micropolarizer array (PMA). Four phase-shifting fringe images can be obtained from a single interference image, thus the vortex beam phase can be o...

The members of viperidae crotalinae (pit viper) family have special pit organs to detect infrared radiation in normal room conditions, whereas most artificial uncooled infrared focal plane arrays (FPAs) operate only in a vacuum chamber. Dissection shows that the pit membrane is a unique substrate-free structure. The temperature rise advantage of th...

Based on the Fourier method, this paper deduces analytic formulae for interpolation bias in digital image correlation, explains the well-known sinusoidal-shaped curves of interpolation bias, and introduces the concept of interpolation bias kernel, which characterizes the frequency response of the interpolation bias and thus provides a measure of th...

The digital image correlation (DIC) method obtains comparable results with strain gauges and its reliability and accuracy are commonly accepted in the measurement of affine deformations. However, in engineering measurements, there are always substantial local deformations with high strain gradients, such as the Portevin-Le Chatelier (PLC) shear ban...

An optical readout focal plane array (FPA) usually has a bent cantilever due to the micro-machining techniques. This bent morphology has a strong negative impact on optical sensitivity, which is a key factor that affects the imaging performance. In this study, an optical readout FPA with a stiffener-supported pixel is presented in order to reduce t...

The out-of-plane deformation of the Portevin-Le Chatelier (PLC) band is investigated during tensile tests in an Al alloy using digital shearography for the first time. The fringe patterns, which reflect the out-of-plane displacement gradient, indicate that the PLC bands also appear in the out-of-plane deformation field corresponding to the serratio...