Dong Sun

• City University of Hong Kong

Soft robots show advantages in flexibility and safe interaction compared with traditional rigid robots. The modular design of soft robots further improves their reconfigurability and easy maintenance. This article presents a soft modular robot based on a rectangular origami structure, which can achieve untethered, controllable, and diverse motions....

This paper proposes a practical micropipette-image (2-D pixel and 3-D spatial coordination) calibration method indispensable to somatic cell microinjection, leveraging advancements in modern motorized micromanipulators. The method determines the depth information of the micropipette in the microscope field by assessing the contact between the micro...

Somatic cell nuclear transfer (SCNT), referred to as somatic cell cloning, is a pivotal biotechnological technique utilized across various applications. Although robotic SCNT is currently available, the subsequent oocyte electrical activation/reconstructed embryo electrofusion is still manually completed by skilled operators, presenting challenges...

The physiology and pathogenesis of biological cells have drawn enormous research interest. Benefiting from the rapid development of microfabrication and microelectronics, miniaturized robots with a tool size below micrometers have widely been studied for manipulating biological cells in vitro and in vivo. Traditionally, the complex physiological en...

The development of microrobots for biomedical applications has enabled tasks such as targeted drug delivery, minimally invasive surgeries, and precise diagnostics. However, effective in vivo navigation and control remain challenging due to their small size and complex body environment. Photoacoustic (PA) and ultrasound (US) imaging techniques, whic...

Aim Scale-aware 3D reconstruction of the surgical scene from a monocular endoscope is important for automatic navigation systems in robot-assisted surgery. However, traditional multi-view stereo methods purely utilize monocular images, which can recover 3D structures arbitrarily scaled with the real world. Current deep learning-based approaches rel...

Laser ablation has been used in different surgical procedures to perform precise treatments. Compared with previous free-beam laser delivery systems, flexible-optical-fiber-based systems can deliver laser energy to a curved space, avoiding the requirement of a straight working path to the target. However, the fiber tip maintains direct contact with...

In vitro blood vessel models are significant for disease modeling, drug assays, and therapeutic development. Microfluidic technologies allow to create physiologically relevant culture models reproducing the features of the in vivo vascular microenvironment. However, current microfluidic technologies are limited by impractical rectangular cross‐sect...

Laser ablation is an effective treatment modality. However, current laser scanners suffer from laser defocusing when scanning targets at different depths in a 3D surgical scene. This study proposes a deep learning-assisted 3D laser steering strategy for minimally invasive surgery that eliminates laser defocusing, increases working distance, and ext...

This research investigates learning-based control of continuum robots in constrained environments without relying on analytical models. We propose a data-efficient stochastic control strategy incorporating online model updates to achieve precise manipulation even when arbitrary robot deformations occur due to environmental interactions. A localized...

The magnetic micromanipulation of swarm microparticles has attracted considerable attention because of its advantages of non-invasiveness, high drug-carrying capacity, and easy observation in the targeted delivery in in-vivo environments. This paper presents an automated control scheme for the magnetic micromanipulation of microswarms in a rotating...

Accurate estimation of absolute depth from a monocular endoscope is a fundamental task for automatic navigation systems in robotic surgery. Previous works solely rely on uni-modal data ( i.e. , monocular images), which can only estimate depth values arbitrarily scaled with the real world. In this paper, we present a novel framework, SADER, which e...

In recent years, magnetic field-controlled microparticles have demonstrated their superiority in biomedical applications. To improve the operation efficiency and imaging effect of microparticles, increasing numbers of researchers are devoted to driving a swarm composed of a group of microparticles. In this study, a new strategy for autonomously man...

The use of natural cartilage extracellular matrix (ECM) has gained widespread attention in the field of cartilage tissue engineering. However, current approaches for delivering functional scaffolds for osteoarthritis (OA) therapy rely on knee surgery, which is limited by the narrow and complex structure of the articular cavity and carries the risk...

Origami provides an opportunity to construct a wide range of 3D functional structures by folding a flat sheet. It can be used to develop various soft functional robots by combining soft smart actuators. However, a simple and an effective model that can address the challenging problem of designing origami patterns to connect origami design with robo...

Capacitive sensors are efficient tools for biophysical force measurement, which is essential for the exploration of cellular behavior. However, attention has been rarely given on the influences of external mechanical and internal electrical interferences on capacitive sensors. In this work, a bionic swallow structure design norm was developed for m...

Multidrug combination therapy provides an effective strategy for malignant tumor treatment. This paper presents the development of a biodegradable microrobot for on‐demand multidrug delivery. By combining magnetic targeting transportation with tumor therapy, it is hypothesized that loading multiple drugs on different regions of a single magnetic mi...

The delivery of nucleic acid vaccine to stimulate host immune responses against Coronavirus disease 2019 shows promise. However, nucleic acid vaccines have drawbacks, including rapid clearance and poor cellular uptake, that limit their therapeutic potential. Microrobots can be engineered to sustain vaccine release and further control the interactio...

This paper reports a soft and scalable crawling robot that can actively adapt to flat planes and tubes without manual adjustment. The robot is mainly composed of a programmable origami body and two flexible electrostatic pads with a measured thickness of around 34 μm. The pad generates considerable adhesion on flat, convex, and concave substrates d...

Recent advancements toward perception and decision-making of flexible endoscopes have shown great potential in computer-aided surgical interventions. However, owing to modeling uncertainty and inter-patient anatomical variation in flexible endoscopy, the challenge remains for efficient and safe navigation in patient-specific scenarios. This paper p...

Despite recent advances in data-independent and deep-learning algorithms, unstained live adherent cell instance segmentation remains a long-standing challenge in cell image processing. Adherent cells' inherent visual characteristics, such as low contrast structures, fading edges, and irregular morphology, have made it difficult to distinguish from...

In existing surgery process, surgeons need to manually adjust the laparoscopes to provide a better field of view (FOV) during operation, which may distract surgeons and slow down the surgery process. Herein, a data‐driven control method that uses a continuum laparoscope to adjust the FOV by tracking the surgical instruments is presented. A Koopman‐...

Microswarms assembled by microparticles have shown promising prospects in targeted delivery. However, the automated manipulation of microswarms remains a considerable challenge due to the limitations of existing in vivo imaging technology. In this article, we design a magnetic tweezer system with a large workspace of 100 mm × 100 mm × 30 mm, whic...

The in vivo manipulation of magnetic microrobots has attracted considerable attention because of its advantages of noninvasiveness and high precision in the targeted delivery. This article presents an automated control scheme for a magnetic microrotor (an anchor-like microrobot), which has the potential for microsurgery and delivery under the gui...

Estimating precise metric depth and scene reconstruction from monocular endoscopy is a fundamental task for surgical navigation in robotic surgery. However, traditional stereo matching adopts binocular images to perceive the depth information, which is difficult to transfer to the soft robotics-based surgical systems due to the use of monocular end...

Magnet-Driven Microrobots In article number 2200118, Dong Sun and co-workers propose a magnetically powered and frictional anisotropy-based microwalker with bioinspired contact feet. The microwalker is constructed by two rigid segments fabricated with 3D laser lithography. It can be well controlled to move in low Reynolds number regimes under an ex...

Many virus-mediated and chemical-based methods for delivering foreign genes into target cells, such as recombinant lentivirus transfection and cationic lipid transfection, are remarkably challenging to use on immune cells because of low efficiency and high toxicity. Microinjection is a promising method to deliver foreign gene expression plasmids in...

Laser energy is commonly used in tissue ablation, wound suturing, and other precise manipulations during surgery. However, currently available laser scanners require further improvements in terms of miniaturization, driving voltage, and stability to steer the laser beam accurately within a constrained environment. Herein, the development of a liqui...

Mitochondrial transfer is a spontaneous process to restore damaged cells in various pathological conditions. The transfer of mitochondria to cell therapy products before their administration can enhance therapeutic outcomes. However, the low efficiency of previously reported methods limits their clinical application. Here, we developed a droplet mi...

This paper presents the development of a novel micro force sensor based on a laterally movable gate field-effect transistor (LMGFET). A precise electrical model is proposed for the performance evaluation of small-scale LMGFET devices and exhibits improved accuracy in comparison with previous models. A novel sandwich structure consisting of a gold c...

Objective: The computation of anatomical information and laparoscope position is a fundamental block of surgical navigation in Minimally Invasive Surgery (MIS). Recovering a dense 3D structure of surgical scene using visual cues remains a challenge, and the online laparoscopic tracking primarily relies on external sensors, which increases system c...

Untethered magnet‐driven microrobots play an increasingly important role in various biomedical applications. Incorporating bionic technology into microrobot design is an emerging way to improve the work efficiency of microrobots. Herein, a magnetically powered and frictional anisotropy‐based microwalker that can be potentially used in in vivo nonli...

Using magnetically powered microagents as precise delivery carriers is a promising technology for targeted therapy. It is a significant challenge to converge microagents to the desired position without sufficient support of real‐time imaging feedback. Herein, a new drive solution is proposed, which generates a rotating gradient‐based magnetic field...

In existing surgery process, surgeons need to manually adjust the laparoscopes to provide a better field of view during operation, which may distract surgeons and slow down the surgery process. This paper presents a data-driven control method that uses a continuum laparoscope to adjust the field of view by tracking the surgical instruments. A Koopm...

In this paper, a high sensitive area-variant type MEMS capacitive sensor was proposed for nano-indentation measurement. The proposed bionic swallow structure processed a high mechanical sensitivity without influences from the load coupling effect. Six comb arrays were optimized and integrated into the proposed sensor with a novel comb sensing confi...

Origami provides an opportunity to construct a wide range of 3D functional structures by folding a flat sheet. It can be used to develop various soft functional robots by combining soft smart actuators. However, an effective method that can address the challenging problem of designing the corresponding flat crease patterns in accordance with the de...

Highly precise micromanipulation tools that can manipulate and interrogate cell organelles and components must be developed to support the rapid development of new cell-based medical therapies, thereby facilitating in-depth understanding of cell dynamics, cell component functions, and disease mechanisms. This paper presents a literature review on m...

Objective: To explore the feasibility and clinical efficacy of a modified medial collateral ligament indentation technique in total knee arthroplasty (TKA) with severe type II valgus deformity. Methods: Consecutive patients with Krackow type II valgus deformity >20° who underwent a primary unilateral TKA between May 2008 and June 2017 were studi...

The non-viral delivery of the prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) nuclease system provides promising solutions for gene therapy. However, traditional chemical and physical delivery approaches for gene knock-in are confronted by significant challenges to overcome the drawbacks of...

Correction for 'Antibody-coated microstructures for selective isolation of immune cells in blood' by Jiyu Li et al., Lab Chip, 2020, 20, 1072-1082, DOI: 10.1039/D0LC00078G.

Soft climbing robots have elicited widespread attention for their potential applications in inspection, maintenance, and search and rescue tasks. However, these robots face challenges in terms of their adaptability and motion capability in various surface environments, such as surfaces with a large gap or nonflat surfaces. In this article, we devel...

Precise force sensing is essential for the mechanical characterization and robotic micromanipulation of biological targets. In this work, a high-resolution MEMS capacitive force sensor was proposed for measuring ultralow multiphysics. A bionic swallow structure that contained multiple feathered comb arrays was designed for reducing chip dimension a...

Despite the rapid development in providing precise delivery of extraneous samples to the vast majority of cells, robotic microinjection is still hindered by cumbersome operations and low throughput in practice. This study presents a new automated microinjection system equipped with two micromanipulators and a deep learning algorithm for cell identi...

Manipulating microrobots to move in a 3-D space is a basic requirement for their in vivo medical applications. In this study, the automatic manipulation of a microrobot in a liquid 3-D space via an electromagnetic coil system is investigated. A path planner is designed to search an optimal path in a 3-D space with obstacles automatically, and a cas...

Cell-carrying magnet-driven microrobots are easily affected by blood flow or body fluids during transportation in the body, and thus cells often fall off from the microrobots. To reduce the loss of loaded cells, we developed a microrobot with a bioactive nanostructured titanate surface (NTS), which enhances cell adhesion. The microrobot was fabrica...

Automatic 3D navigation control of microrobot in large microenvironment is one of the primary challenges hindering its applications. In this article, we present a systematic approach to use an electromagnetic manipulation system to deal with this challenge. Two movable orthogonal microscopic cameras scan the microenvironment on the top view and sid...

The computation of anatomical information and laparoscope position is a fundamental block of robot-assisted surgical navigation in Minimally Invasive Surgery (MIS). Recovering a dense 3D structure of surgical scene using visual cues remains a challenge, and the online laparoscopic tracking mostly relies on external sensors, which increases system c...

Mitochondrial Transfer In article number 2103086, Gang Li, Dong Sun, and co-workers present a novel method of controlling the quality and quantity of mitochondria transferred to single cells using an automated optical tweezer-based micromanipulation system. The transfer of isolated mitochondria from fetal mesenchymal stem cells (fMSCs) to adult mes...

Single-cell level coculture facilitates the study of cellular interactions for uncovering unknown physiological mechanisms, which are crucial for the development of new therapies for diseases. However, efficient approaches for high-throughput deterministic pairing of single cells and traceable coculture remain lacking. In this study, we report a ne...

Navigation control of microrobots in vivo has great potential in precision medicine and has attracted considerable attention in recent years. The control performance of the existing methods is considerably affected by hysteresis nonlinearity. This article presents a robust control method that can overcome hysteresis influence in navigating a micror...

Mitochondrial dysfunction is considered to be an important factor that leads to aging and premature aging diseases. Transferring mitochondria to cells is an emerging and promising technique for the therapy of mitochondrial deoxyribonucleic acid (mtDNA)‐related diseases. This paper presents a unique method of controlling the quality and quantity of...

Microrobots with simultaneously improved degradability and mechanical strength are highly demanded in performing in vivo delivery tasks in clinical applications. The properties of degradability and mechanical strength are contradictory for many materials used to make microrobots. This article proposes a new design that can result in 3D cell culture...

Introduction of a gene to mesenchymal stem cells (MSCs) is a well-known strategy to purposely manipulate the cell fate and further enhance therapeutic performance in cell-based therapy. Viral and chemical approaches for gene delivery interfere with differentiation potential. Although microinjection as a physical delivery method is commonly used for...

Microrobots-assisted drug delivery and surgery have been always in the spotlight and are highly anticipated to solve the challenges of cancer in situ treatment. These versatile small biomedical robots are expected to realize direct access to the tumor or disease site for precise treatment, which requires real-time and high-resolution in vivo tracki...

Magnetically powered microswimmers exhibit various advantages in practical applications, including simplified propulsion mechanism of nonreciprocal motion in a low Reynolds (Re) number environment, high flexibility, and high efficiency. Inspired by the morphological and dynamic analyses of microscale nonreciprocal locomotion, this study characteriz...

Continuum manipulators with structural compliance can be utilized to steer a laser beam in constrained environments. However, the flexibility and nonlinear characteristics of continuum manipulators bring difficulty in precision manipulation. This study proposes a model-free control approach with visual feedback to control a tendon-driven flexible m...

This chapter reports a study on the laser-induced fusion of human embryonic stem cells (hESCs) at the single-cell level. Cells were manipulated by optical tweezers and fused under irradiation with pulsed UV laser at 355 nm. Successful fusion was indicated by green fluorescence protein transfer. The influence of laser pulse energy on the fusion effi...

This chapter presents a stable control framework for cell transportation using robot-aided optical tweezers. By incorporating saturation functions into a PID controller and utilizing a velocity observer, cell position can asymptotically converge to the desired values. The proposed control approach also guarantees that the trapped cell can always st...

With an increased demand for various cell-based clinical applications and drug discovery, an enabled technology that can automatically locate and pair biological cells from different groups, with high precision and throughput, is highly demanded. This chapter presents a novel approach to achieve such cell pairing manipulation using an automatically...

In many cell surgery applications, cell must be oriented properly such that the microsurgery tool can access the target components with minimum damage to the cell. In this chapter, a scheme for out of image plane orientation control of suspended biological cells using robotic controlled optical tweezers is presented for orientation-based cell surge...

This study investigates the use of a tendon-driven continuum robot to deform a soft object, whereas the robot body is deformed into an arbitrary shape to adapt to a constrained environment. A dynamic estimator (DE) is developed to approximate the Jacobian matrix that associates the actuator input with the deformed output of the soft object. This he...

Intracellular micromanipulation assisted by robotic systems has valuable applications in biomedical research, such as genetic diagnosis and genome-editing tasks. However, current studies suffer from a low success rate and a large operation damage because of insufficient information on the operation information of targeted specimens. The complexity...

Precise delivery of therapeutic cells to the desired site in vivo is an emerging and promising cellular therapy in precision medicine. This paper presents the development of a magnet‐driven and image‐guided degradable microrobot that can precisely deliver engineered stem cells for orthotopic liver tumor treatment. The microrobot employs a burr‐like...

The use of microrobots to achieve micromanipulation in vivo has attracted considerable attention in recent years to meet the request of non-invasiveness, precision and high efficiency in medical treatment. This letter reports the use of a home-designed electromagnetic manipulation system to control the movements of microrobots in a simulated vasc...

Precise intracellular delivery is essential for many biomedical applications, such as genome editing and intracellular mechanism investigation. This paper presents the development of an automated intracellular delivery approach using a robot-aided microscope system with 3D reconstruction information. A series of optical section images are sampled b...

Combining patterning coculture technique with microfluidics enables the reconstruction of complex in-vivo system to facilitate in-vitro studies on cell-cell and cell-environment interactions. However, simple and versatile approaches for patterning coculture of cells on microfluidic platforms remain lacking. In this study, a novel gravitational sedi...

The propulsive efficiency and biodegradability of wireless microrobots play a significant role in facilitating promising biomedical applications. Mimicking biological matters is a promising way to improve the performance of microrobots. Among diverse locomotion strategies, undulatory propulsion shows remarkable efficiency and agility. This work pro...

Cell isolation from blood is an important process of diagnosing immune diseases. There are still demands on a user-friendly approach to achieve high cell extraction efficiency and purity of a target immune cell subtype for more promising diagnosis and monitoring. For selective immune cell isolation, we developed a microstructured device, which cons...

Automated microinjection systems for suspension cells have been studied for years. Nevertheless, microinjection systems for adherent cells still suffer from laborious manual operations and low productivity. This paper presents a new automated microinjection system with high productivity for adherent cells. This system enhances productivity through...

Objective: The application of in vivo microrobot navigation has received considerable attention from the field of precision therapy, which uses microrobots in living organisms. Methods: This study investigates the navigation of microrobots in vivo using optical coherence tomography (OCT) imaging feedback. The electromagnetic gradient field gener...

The accurate delivery of precise amounts of drugs to a specific location can considerably affect various clinical applications. The precise control of drug amount and position is crucial to a successful drug delivery. This paper proposes the use of poly(lactide-co-glycolicacid) (PLGA)-based microspheres to contain precise amounts of drugs and an op...

Microrobots show great targeted-delivery potential in precision medicine. This paper presents the use of a model-free approach to the navigation control of a microrobot in the cardiovascular environment. With the proposed approach, the microrobot can adapt to the non-Newton behaviour of blood and environmental disturbances when it moves in blood ve...

Electromagnetic-based actuation is receiving increasing attention for driving microparticles, particularly for in vivo biomedical applications. This study presents a core shape design for electromagnetic coils to develop a magnetic gradient field-based actuation system that can enable microrobotic manipulation. Based on mathematical model using the...

Optical tweezers are widely used for noninvasive and precise micromanipulation of living cells to understand biological processes. By focusing laser beams on cells, direct cell manipulation with optical tweezers can achieve high precision and flexibility. However, direct exposure to the laser beam can lead to negative effects on the cells. These ph...

Mimicking biological locomotion strategies offers important possibilities and motivations for robot design and control methods. Among bioinspired microrobots, flexible microrobots exhibit remarkable efficiency and agility. These microrobots traditionally rely on soft material components to achieve undulatory propulsion, which may encounter challeng...

Multiple degrees‐of‐freedom (multi‐DOF) cell orientation control is a vital important technique involved in single cell surgery applications. Currently, few studies have been performed toward automation of multi‐DOF cell orientation control using robotically controlled optical tweezers. In this paper, a robust control framework is developed to perf...

Optical cell manipulation has become increasingly valuable in cell-based assays. In this paper, we demonstrate the translational and rotational manipulation of filamentous cells using multiple cooperative microrobots automatically driven by holographic optical tweezers. The photodamage of the cells due to direct irradiation of the laser beam can be...

Fracture remains one of the most common traumatic conditions in orthopedic surgery. The use of mesenchymal stem cells (MSCs) to augment fracture repair is promising. Leucine‐rich repeat‐containing GPCR 5 (Lgr5), a transmembrane protein, has been identified as a novel adult stem cell marker in various organs and tissues. However, the roles of Lgr5 i...

In vivo manipulation of microparticles, such as biological cells and drugs, has attracted considerable attention in recent years. This paper presents the development of robot-aided manipulation technology that can control targeted microparticles to move a relatively long distance in in vivo environment. The field of view can be updated online, such...

A novel micro force sensor based on depletion type vertically movable gate array field effect transistor (VMGAFET) was developed with cross-axis decoupling structure and eight gate arrays. This novel sensor is able to detect ultra-low force and exhibit high measuring sensitivity. An accurate electrical model was then proposed and compared with a lo...

Intracellular surgery suffers from a low success rate due to the lack of 3D position feedback of the selected organelles. In this study, we developed a novel robot-aided microscopy system and 3D reconstruction algorithm to conduct intracellular surgery with 3D information. A series of optical sections along the vertical direction was obtained by mi...

Single cell surgery such as manipulation or removal of subcellular components or/and organelles from single cells is increasingly used for the study of diseases and their causes in precision medicine. This paper presents a robotic surgery system to achieve automated organelle biopsy of single cells with dimensions of less than 20 μm in diameter. Th...

Mesenchymal stromal/stem cells (MSCs) are easily obtained multipotent cells that are widely applied in regenerative medicine. Electrical stimulation (ES) has a promoting effect on bone healing and osteogenic differentiation of MSCs. Direct and alternating currents (AC) are extensively used to promote the osteogenic differentiation of MSCs in vivo...

Intracellular delivery of functional materials holds great promise in biologic research and therapeutic applications but poses challenges to existing techniques, including the reliance on exogenous vectors and lack of selectivity. To address these problems, we propose a vector-free approach that utilizes millimeter-sized iron rods or spheres driven...