A magnetic field, which is transparent and relatively safe to biological tissue, is a powerful tool for remote actuation and wireless control of magnetic devices. Furthermore, miniature robots can ...access complex and narrow regions of the human body as well as manipulate down to subcellular entities; however, integrating onboard components is difficult due to their limited size. Combining these two technologies, magnetic miniature robots have undergone rapid development during the past two decades, mainly because of their high potential in medical and bioengineering applications. To improve the scientific and clinical outcomes of these tiny agents, developing suitable and reliable actuation systems is essential. As a newly emerging field that has progressed in recent years, magnetic actuation systems offer a harmless and effective approach for the remote control of miniature robots via a dynamic magnetic field. Herein, a review on the state‐of‐the‐art magnetic actuation systems for miniature robots is presented with the goal of providing readers with a better understanding of magnetic actuation and guidance for future system design.
Magnetic miniature robots have shown potential in medical and bioengineering applications. To improve their scientific and clinical outcomes, developing suitable and reliable actuation systems is essential. Herein, a review on the state‐of‐the‐art magnetic actuation systems for miniature robots is presented with the goal of providing readers a better understanding of magnetic actuation and guidance for future system design.
Locomotion of Miniature Soft Robots Ng, Chelsea Shan Xian; Tan, Matthew Wei Ming; Xu, Changyu ...
Advanced materials (Weinheim),
05/2021, Letnik:
33, Številka:
19
Journal Article
Recenzirano
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Miniature soft robots are mobile devices, which are made of smart materials that can be actuated by external stimuli to realize their desired functionalities. Here, the key advancements and ...challenges of the locomotion producible by miniature soft robots in micro‐ to centimeter length scales are highlighted. It is highly desirable to endow these small machines with dexterous locomotive gaits as it enables them to easily access highly confined and enclosed spaces via a noninvasive manner. If miniature soft robots are able to capitalize this unique ability, they will have the potential to transform a vast range of applications, including but not limited to, minimally invasive medical treatments, lab‐on‐chip applications, and search‐and‐rescue missions. The gaits of miniature soft robots are categorized into terrestrial, aquatic, and aerial locomotion. Except for the centimeter‐scale robots that can perform aerial locomotion, the discussions in this report are centered around soft robots that are in the micro‐ to millimeter length scales. Under each category of locomotion, prospective methods and strategies that can improve their gait performances are also discussed. This report provides critical analyses and discussions that can inspire future strategies to make miniature soft robots significantly more agile.
Miniature soft robots are made of smart materials that can be actuated by external stimuli to realize their desired functionalities. Critical analyses and discussions on the locomotion producible by soft robots in micro‐ to centimeter length scales are provided, with the aim of inspiring future development of miniature soft robots that can be significantly more dexterous and robust.
Magnetic miniature robots have great potential to create a paradigm shift for robotics, materials science, and biomedicine because they can non‐invasively access highly confined and enclosed spaces ...to perform a vast range of small‐scale manipulation tasks. In article number 2100170, Guo Zhan Lum and co‐workers introduce optimal magnetic miniature robots that can display unprecedented dexterity, manipulation capabilities, and functionalities.
Magnetically actuated miniature robots are limited in their mechanical outputting capability, because the magnetic forces decrease significantly with decreasing robot size and increasing actuating ...distance. Hence, the output force of these robots can hardly meet the demand for specific biomedical applications (e.g., tissue penetration). This article proposes a tetherless magnetic impact needle robot (MINRob) based on a triple-magnet system with reversible and repeatable magnetic collisions to overcome this constraint on output force. The working procedure of the proposed system is divided into several states, and a mathematical model is developed to predict and optimize the force output. These force values in magnetic impact and penetration are obtained from a customized setup, indicating a 10-fold increase compared with existing miniature robots that only utilize magnetic attractive force. Eventually, the proposed MINRob is integrated with a teleoperation system, enabling remote and precise control of the robot's position and orientation. The triple-magnet system offers promising locomotion patterns and penetration capacity via the notably increased force output, showing great potential in robot-assisted tissue penetration in minimally invasive healthcare.
Magnetic miniature robots (MMRs) are small‐scale, untethered actuators which can be controlled by magnetic fields. As these actuators can non‐invasively access highly confined and enclosed spaces; ...they have great potential to revolutionize numerous applications in robotics, materials science, and biomedicine. While the creation of MMRs with six‐degrees‐of‐freedom (six‐DOF) represents a major advancement for this class of actuators, these robots are not widely adopted due to two critical limitations: i) under precise orientation control, these MMRs have slow sixth‐DOF angular velocities (4 degree s−1) and it is difficult to apply desired magnetic forces on them; ii) such MMRs cannot perform soft‐bodied functionalities. Here a fabrication method that can magnetize optimal MMRs to produce 51–297‐fold larger sixth‐DOF torque than existing small‐scale, magnetic actuators is introduced. A universal actuation method that is applicable for rigid and soft MMRs with six‐DOF is also proposed. Under precise orientation control, the optimal MMRs can execute full six‐DOF motions reliably and achieve sixth‐DOF angular velocities of 173 degree s−1. The soft MMRs can display unprecedented functionalities; the six‐DOF jellyfish‐like robot can swim across barriers impassable by existing similar devices and the six‐DOF gripper is 20‐folds quicker than its five‐DOF predecessor in completing a complicated, small‐scale assembly.
Magnetic miniature robots (MMRs) are small, untethered actuators that can be controlled by magnetic fields. This work introduces optimal MMRs that can display unprecedented dexterity, manipulation capabilities, and soft‐bodied mechanical functionalities. It is envisioned that this work can inspire future MMRs to be significantly more competent across a vast range of applications in robotics, materials science, and biomedicine.
Untethered soft miniature robots capable of accessing hard-to-reach regions can enable new, disruptive, and minimally invasive medical procedures. However, once the control input is removed, these ...robots easily move from their target location because of the dynamic motion of body tissues or fluids, thereby restricting their use in many long-term medical applications. To overcome this, we propose a wireless spring-preloaded barbed needle release mechanism, which can provide up to 1.6 N of force to drive a barbed needle into soft tissues to allow robust on-demand anchoring on three-dimensional (3D) surfaces. The mechanism is wirelessly triggered using radio-frequency remote heating and can be easily integrated into existing untethered soft robotic platforms without sacrificing their mobility. Design guidelines aimed at maximizing anchoring over the range of the most biological tissues (kPa range) and extending the operating depth of the device inside the body (up to 75%) are also presented. Enabled by these advances, we achieve robust anchoring on a variety of ex vivo tissues and demonstrate the usage of such a device when integrated with existing soft robotic platforms and medical imaging. Moreover, by simply changing the needle, we demonstrate additional functionalities such as controlled detachment and subsurface drug delivery into 3D cancer spheroids. Given these capabilities, our proposed mechanism could enable the development of a new class of biomedical-related functionalities, such as local drug delivery, disease monitoring, and hyperthermia for future untethered soft medical robots.
Magnetic miniature robots are promising tools for minimally invasive and noninvasive therapy. Constructing systems with actuation-perception loops is an essential step to progress from fundamental ...research to clinical applications, and from manual to automated manipulation. Such systems include imaging devices for tracking miniature robots inside a living body, and magnetic actuators for manipulating the robots. In this survey article, the designs, features, and control of various magnetic actuation systems with imaging modalities are summarized. The strategies of actuation-perception cooperation are discussed from both hardware and software aspects, aiming to provide a paradigm for building automated image-guided systems in clinical scenarios. Furthermore, the solutions when both the systems and surgeons simultaneously participate in the operation are introduced. We also discuss the advantages and drawbacks of reported techniques, major challenges, and potential prospects in this field.
A simple-structured, low-cost miniature robot is highly desired for swarm robotics research. In this article, we designed an underactuated miniature robot using only one motor, named as SimoBot, to ...save space, cost, weight, and energy consumption. Since it has only one motor but needs to travel on the 2-D ground, the design, moving mechanism, and control are all challenging. We conceived a movement strategy based on the interplaying between the centrifugal force and swinging motion of the robot to generate translation and rotation on the ground and finally follow various arbitrary paths. This robot has only five simple components-a vibration motor, a button cell, a microcontroller board, four-pin legs (one of which is shorter than the others), and sensors. This article built the kinematics and kinetics models and analyzed and optimized the parameters. The prototype weighs only 4.76 g, costs 4.7 dollars, and is 20 mm in diameter and 18 mm in height. It can run as fast as 40 mm/s. Its cost of transportation is only 55, smaller than most miniature robots with onboard power and insects. By modulating voltage polarities on the motor and the periods, we demonstrated the controllability of SimoBot by the movement along a straight line, a circle, an "S" curve, and more arbitrary trajectories.
In this work, the dynamics of ”n” legged modular miniature robots with a soft body is modeled. The dynamic formulation is obtained using Newton–Euler formulation that depends on the contact ...parameters and the feet closed-chain kinematic analysis. The dynamic model determines the locomotion parameters of each module as an individual system as well as the dynamics of the whole robot in a 3D space; i.e., the robot is modeled as one system, and modules are considered to be sets of flexible links connected within this system. Kinematic constraints among these modules are obtained by considering the type of backbone integrated into the modular robot. Various types of backbones are used that are classified into three groups: rigid, only torsional, and soft. The model is verified using SMoLBot, an origami-inspired miniature robot made of multiple modules and soft/rigid backbones. Additional to the dynamic model, the effect of different sets of design parameters on the locomotion of the legged soft-bodied modular miniature robots is studied. Analyses comparing the velocity of SMoLBot with a different number of modules and various types of backbones are presented using the proposed dynamic model. Our results show the existence of an optimum backbone torsional stiffness for legged miniature modular robots and an optimum number of legs for a given backbone stiffness that maximizes the robot’s velocity. In this research, presented results and locomotion study show that the robot’s design should be iteratively improved based on specific optimum goals for exclusively defined task to satisfy the operational needs.
•Dynamic modeling of legged modular miniature robots.•Rigid and soft body dynamics.•Locomotion characteristics of multi-legged miniature robots with different numbers of modules and body stiffnesses.•The effect of soft backbones on miniature robot’s locomotion.
This paper presents a linear quadratic Gaussian (LQG) controller for controlling the gait of a miniature, foldable quadruped robot with individually actuated and controlled legs (MinIAQ-III). The ...controller is implemented on a palm-size robot made by folding an acetate sheet. MinIAQ-III has four DC motors for actuation and four rotary sensors for feedback. It is one of the few untethered robots on a miniature scale capable of working with different gaits with the help of its individually-actuated legs and the developed controller. The presented LQG controller controls each leg's positions and rotational speeds by measuring the positions and estimating the rotational speeds, respectively. With the precise gait control on the robot, we demonstrate different gaits inspired by quadrupeds in nature and compare the simulation and experiment results for some of the gaits. An extensive simulation environment developed for robot dynamics helps us to predict the locomotion behavior of the robot in various environments. The match between the simulation and the experiment results shows that the proposed LQG controller can successfully control the miniature robot's gaits. We also conduct a case study that shows the potential to use the simulation to achieve different robot behavior. In a case study, we present our robot performing a prancing similar to horses. We use the simulation environment to find the required motor configuration phases and physical parameters, which can make our robot prance. After finding the parameters in simulation, we replicate the configuration in our robot and observe the robot making the same moves as the simulation.
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