10 research outputs found

    マルチ スケール キノウ ヲ ユウスル コウソク ジドウ マイクロ マニピュレーション システム

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    Ebubekir Avci, Chanh-Nghiem Nguyen, Kenichi Ohara, Yasushi Mae, Tatsuo Arai, Analysis and suppression of residual vibration in microhand for high-speed single-cell manipulation, International Journal of Mechatronics and Automation, 2013-Vol.3, No.2, pp.110-11

    Elastic Inflatable Actuators for Soft Robotic Applications

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    The 20th century’s robotic systems have been made out of stiff materials and much of the developments in the field have pursued ever more accurate and dynamic robots which thrive in industrial automation settings and will probably continue to do so for many decades to come. However, the 21st century’s robotic legacy may very well become that of soft robots. This emerging domain is characterized by continuous soft structures that simultaneously fulfil the role of robotic link and robotic actuator, where prime focus is on design and fabrication of the robotic hardware instead of software control to achieve a desired operation. These robots are anticipated to take a prominent role in delicate tasks where classic robots fail, such as in minimally invasive surgery, active prosthetics and automation tasks involving delicate irregular objects. Central to the development of these robots is the fabrication of soft actuators to generate movement. This paper reviews a particularly attractive type of soft actuators that are driven by pressurized fluids. These actuators have recently gained substantial traction on the one hand due to the technology push from better simulation tools and new manufacturing technologies including soft-lithography and additive manufacturing, and on the other hand by a market pull from the applications listed above. This paper provides an overview of the different advanced soft actuator configurations, their design, fabrication and applications.This research is supported by the Fund for Scientific Research-Flanders (FWO), and the European Research Council (ERC starting grant HIENA)

    Elastic Inflatable Actuators for Soft Robotic Applications

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    The 20th century’s robotic systems have been made out of stiff materials and much of the developments in the field have pursued ever more accurate and dynamic robots which thrive in industrial automation settings and will probably continue to do so for many decades to come. However, the 21st century’s robotic legacy may very well become that of soft robots. This emerging domain is characterized by continuous soft structures that simultaneously fulfil the role of robotic link and robotic actuator, where prime focus is on design and fabrication of the robotic hardware instead of software control to achieve a desired operation. These robots are anticipated to take a prominent role in delicate tasks where classic robots fail, such as in minimally invasive surgery, active prosthetics and automation tasks involving delicate irregular objects. Central to the development of these robots is the fabrication of soft actuators to generate movement. This paper reviews a particularly attractive type of soft actuators that are driven by pressurized fluids. These actuators have recently gained substantial traction on the one hand due to the technology push from better simulation tools and new manufacturing technologies including soft-lithography and additive manufacturing, and on the other hand by a market pull from the applications listed above. This paper provides an overview of the different advanced soft actuator configurations, their design, fabrication and applications.This research is supported by the Fund for Scientific Research-Flanders (FWO), and the European Research Council (ERC starting grant HIENA)

    Scalability study for robotic hand platform

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    The goal of this thesis project was to determine the lower limit of scale for the RIT robotic grasping hand. This was accomplished using a combination of computer simulation and experimental studies. A force analysis was conducted to determine the size of air muscles required to achieve appropriate contact forces at a smaller scale. Input variables, such as the actuation force and tendon return force, were determined experimentally. A dynamic computer model of the hand system was then created using Recurdyn. This was used to predict the contact (grasping) force of the fingers at full-scale, half-scale, and quarter-scale. Correlation between the computer model and physical testing was achieved for both a life-size and half-scale finger assembly. To further demonstrate the scalability of the hand design, both half and quarter-scale robotic hand rapid prototype assemblies were built using 3D printing techniques. This thesis work identified the point where further miniaturization would require a change in the manufacturing process to micro-fabrication. Several techniques were compared as potential methods for making a production intent quarter-scale robotic hand. Investment casting, Swiss machining, and Selective Laser Sintering were the manufacturing techniques considered. A quarter-scale robotic hand tested the limits of each technology. Below this scale, micro-machining would be required. The break point for the current actuation method, air muscles, was also explored. Below the quarter-scale, an alternative actuation method would also be required. Electroactive Polymers were discussed as an option for the micro-scale. In summary, a dynamic model of the RIT robotic grasping hand was created and validated as scalable at full and half-scales. The model was then used to predict finger contact forces at the quarter-scale. The quarter-scale was identified as the break point in terms of the current RIT robotic grasping hand based on both manufacturing and actuation. A novel, prototype quarter-scale robotic hand assembly was successfully built by an additive manufacturing process, a high resolution 3D printer. However, further miniaturization would require alternate manufacturing techniques and actuation mechanisms

    Cyber-Physical Systems for Micro-/Nano-assembly Operations: a Survey

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    Abstract Purpose of Review Latest requirements of the global market force manufacturing systems to a change for a new production paradigm (Industry 4.0). Cyber-Physical Systems (CPS) appear as a solution to be deployed in different manufacturing fields, especially those with high added value and technological complexity, high product variants, and short time to market. In this sense, this paper aims at reviewing the introduction level of CPS technologies in micro/nano-manufacturing and how these technologies could cope with these challenging manufacturing requirements. Recent Findings The introduction of CPS is still in its infancy on many industrial applications, but it actually demonstrates its potential to support future manufacturing paradigm. However, only few research works in micro/nano-manufacturing considered CPS frameworks, since the concept barely appeared a decade ago. Summary Some contributions have revealed the potential of CPS technologies to improve manufacturing performance which may be scaled to the micro/nano-manufacturing. IoT-based frameworks with VR/AR technologies allow distributed and collaborative systems, or agent-based architectures with advance algorithm implementations that improve the flexibility and performance of micro-/nano-assembly operations. Future research of CPS in micro-/nano-assembly operations should be followed by more studies of its technical deployment showing its implications under other perspectives, i.e. sustainable, economic, and social point of views, to take full advance of all its features

    Control techniques for mechatronic assisted surgery

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    The treatment response for traumatic head injured patients can be improved by using an autonomous robotic system to perform basic, time-critical emergency neurosurgery, reducing costs and saving lives. In this thesis, a concept for a neurosurgical robotic system is proposed to perform three specific emergency neurosurgical procedures; they are the placement of an intracranial pressure monitor, external ventricular drainage, and the evacuation of chronic subdural haematoma. The control methods for this system are investigated following a curiosity led approach. Individual problems are interpreted in the widest sense and solutions posed that are general in nature. Three main contributions result from this approach: 1) a clinical evidence based review of surgical robotics and a methodology to assist in their evaluation, 2) a new controller for soft-grasping of objects, and 3) new propositions and theorems for chatter suppression sliding mode controllers. These contributions directly assist in the design of the control system of the neurosurgical robot and, more broadly, impact other areas outside the narrow con nes of the target application. A methodology for applied research in surgical robotics is proposed. The methodology sets out a hierarchy of criteria consisting of three tiers, with the most important being the bottom tier and the least being the top tier. It is argued that a robotic system must adhere to these criteria in order to achieve acceptability. Recent commercial systems are reviewed against these criteria, and are found to conform up to at least the bottom and intermediate tiers. However, the lack of conformity to the criteria in the top tier, combined with the inability to conclusively prove increased clinical benefit, particularly symptomatic benefit, is shown to be hampering the potential of surgical robotics in gaining wide establishment. A control scheme for soft-grasping objects is presented. Grasping a soft or fragile object requires the use of minimum contact force to prevent damage or deformation. Without precise knowledge of object parameters, real-time feedback control must be used to regulate the contact force and prevent slip. Moreover, the controller must be designed to have good performance characteristics to rapidly modulate the fingertip contact force in response to a slip event. A fuzzy sliding mode controller combined with a disturbance observer is proposed for contact force control and slip prevention. The robustness of the controller is evaluated through both simulation and experiment. The control scheme was found to be effective and robust to parameter uncertainty. When tested on a real system, however, chattering phenomena, well known to sliding mode research, was induced by the unmodelled suboptimal components of the system (filtering, backlash, and time delays). This reduced the controller performance. The problem of chattering and potential solutions are explored. Real systems using sliding mode controllers, such as the control scheme for soft-grasping, have a tendency to chatter at high frequencies. This is caused by the sliding mode controller interacting with un-modelled parasitic dynamics at the actuator-input and sensor-output of the plant. As a result, new chatter-suppression sliding mode controllers have been developed, which introduce new parameters into the system. However, the effect any particular choice of parameters has on system performance is unclear, and this can make tuning the parameters to meet a set of performance criteria di cult. In this thesis, common chatter-suppression sliding mode control strategies are surveyed and simple design and estimation methods are proposed. The estimation methods predict convergence, chattering amplitude, settling time, and maximum output bounds (overshoot) using harmonic linearizations and invariant ellipsoid sets

    Hybrid optical and magnetic manipulation of microrobots

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    Microrobotic systems have the potential to provide precise manipulation on cellular level for diagnostics, drug delivery and surgical interventions. These systems vary from tethered to untethered microrobots with sizes below a micrometer to a few microns. However, their main disadvantage is that they do not have the same capabilities in terms of degrees-of-freedom, sensing and control as macroscale robotic systems. In particular, their lack of on-board sensing for pose or force feedback, their control methods and interface for automated or manual user control are limited as well as their geometry has few degrees-of-freedom making three-dimensional manipulation more challenging. This PhD project is on the development of a micromanipulation framework that can be used for single cell analysis using the Optical Tweezers as well as a combination of optical trapping and magnetic actuation for recon gurable microassembly. The focus is on untethered microrobots with sizes up to a few tens of microns that can be used in enclosed environments for ex vivo and in vitro medical applications. The work presented investigates the following aspects of microrobots for single cell analysis: i) The microfabrication procedure and design considerations that are taken into account in order to fabricate components for three-dimensional micromanipulation and microassembly, ii) vision-based methods to provide 6-degree-offreedom position and orientation feedback which is essential for closed-loop control, iii) manual and shared control manipulation methodologies that take into account the user input for multiple microrobot or three-dimensional microstructure manipulation and iv) a methodology for recon gurable microassembly combining the Optical Tweezers with magnetic actuation into a hybrid method of actuation for microassembly.Open Acces

    The development of optical nanomachines for studying molecules : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Mechatronics Engineering at Massey University, Palmerston North, New Zealand

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    Chapter 3 is ©2020 IEEE. Accepted manuscript is reprinted, with permission, from 2020 IEEE/ASME International Conference on Advanced Intelligent Mechatronics (AIM). Chapter 5 is ©2022 IEEE. Accepted manuscript is reprinted, with permission, from 2022 International Conference on Manipulation, Automation and Robotics at Small Scales (MARSS).Optical tweezers have been used for a number of applications since their invention by Arthur Ashkin in 1986, and are particularly useful for biological and biophysical studies due to their exceptionally high spatial and force-based resolution. The same intense laser focus that allows light to be used as a tool for micro-nanoscale manipulation also has the potential to damage the objects being studied, and the extremely high force resolution is coupled with the limitation of very low forces. There is potential to overcome these drawbacks of optical manipulation through making use of another laser based technique: two-photon absorption polymerisation (TPAP). This thesis has brought these together to demonstrate the uses of optical nanomachines as helpful tools for optical tweezer studies. The project was highly interdisciplinary, concerning the intersection of optical trapping, 3D micromachine design and development, and DNA stretching. The thesis was based around the strategy of first developing microrobots and demonstrating their manipulation using optical tweezers, then adjusting the design for specific applications. Microlevers were developed for lever-assisted DNA stretching and amplification of optical forces. The influence of design features and TPAP parameters on microlever functionality was investigated; particularly the influence of overlapping area and presence of supports, and the effects of differently shaped "trapping handles". These features were important as lever functionality was tested in solutions of different ionic strength, and stable trapping of the levers was required for force amplification. DNA stretching was chosen as a target application for distanced-application of optical forces due to its status as a well-known and characterised example of single-molecule studies with optical tweezers. Amplification of optical forces was also seen as an application that could demonstrate the utility of optical micromachines, and microlevers with a 2:1 lever arm ratio were developed to produce consistent, two-fold amplification of optical forces, in a first for unsupported, pin-jointed optical microrobotics. It is hoped that in the future fully-remote, micromachine-assisted studies will extend optical tweezer studies of laser-sensitive subjects, as well as increasing the forces that can be applied, and the results obtained in this thesis are encouraging. All in all, the thesis confirms the potential of optical micromachines for aiding studies using optical tweezers, and demonstrates concrete progress in both design and application
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