Amith Mudugamuwa
University of Moratuwa, Sri Lanka, Centre for Advanced Mechatronic Systems, Department Member
Research Interests:
Multiple robots are used in robotic applications to achieve tasks that are impossible to perform as individual robotic modules. At the microscale/nanoscale, controlling multiple robots is difficult due to the limitations of fabrication... more
Multiple robots are used in robotic applications to achieve tasks that are impossible to perform as individual robotic modules. At the microscale/nanoscale, controlling multiple robots is difficult due to the limitations of fabrication technologies and the availability of on-board controllers. This highlights the requirement of different approaches compared to macro systems for a group of microrobotic systems. Current microrobotic systems have the capability to form different configurations, either as a collectively actuated swarm or a selectively actuated group of agents. Magnetic, acoustic, electric, optical, and hybrid methods are reviewed under collective formation methods, and surface anchoring, heterogeneous design, and non-uniform control input are significant in the selective formation of microrobotic systems. In addition, actuation principles play an important role in designing microrobotic systems with multiple microrobots, and the various control systems are also reviewed...
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This paper comprehensively studies the latest progress in microfluidic technology for submicron and nanoparticle manipulation by elaborating on the physics, device design, working mechanism and applications of microfluidic technologies.
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Nature consists of numerous solutions to overcome challenges in designing artificial systems. Various actuation mechanisms have been implemented in microrobots to mimic the motion of microorganisms. Such bio-inspired designs have... more
Nature consists of numerous solutions to overcome challenges in designing artificial systems. Various actuation mechanisms have been implemented in microrobots to mimic the motion of microorganisms. Such bio-inspired designs have contributed immensely to microscale developments. Among the actuation mechanisms, magnetic actuation is widely used in bio-inspired microrobotic systems and related propulsion mechanisms used by microrobots to navigate inside a magnetic field and are presented in this review. In addition, the considered robots are in microscale, and they can swim inside a fluidic environment with a low Reynolds number. In relation to microrobotics, mimicry of bacteria flagella, sperm flagella, cilia, and fish are significant. Due to the fact that these biological matters consist of different propulsion mechanisms, the effect of various parameters was investigated in the last decade and the review presents a summary that enhances understanding of the working principle of pro...
Research Interests:
Nature consists of numerous solutions to overcome challenges in designing artificial systems. Various actuation mechanisms have been implemented in microrobots to mimic the motion of microorganisms. Such bio-inspired designs have... more
Nature consists of numerous solutions to overcome challenges in designing artificial systems. Various actuation mechanisms have been implemented in microrobots to mimic the motion of microorganisms. Such bio-inspired designs have contributed immensely to microscale developments. Among the actuation mechanisms, magnetic actuation is widely used in bio-inspired microrobotic systems and related propulsion mechanisms used by microrobots to navigate inside a magnetic field and are presented in this review. In addition, the considered robots are in microscale, and they can swim inside a fluidic environment with a low Reynolds number. In relation to microrobotics, mimicry of bacteria flagella, sperm flagella, cilia, and fish are significant. Due to the fact that these biological matters consist of different propulsion mechanisms, the effect of various parameters was investigated in the last decade and the review presents a summary that enhances understanding of the working principle of pro...
Research Interests:
Nature consists of numerous solutions to overcome challenges in designing artificial systems. Various actuation mechanisms have been implemented in microrobots to mimic the motion of microorganisms. Such bio-inspired designs have... more
Nature consists of numerous solutions to overcome challenges in designing artificial systems. Various actuation mechanisms have been implemented in microrobots to mimic the motion of microorganisms. Such bio-inspired designs have contributed immensely to microscale developments. Among the actuation mechanisms, magnetic actuation is widely used in bio-inspired microrobotic systems and related propulsion mechanisms used by microrobots to navigate inside a magnetic field and are presented in this review. In addition, the considered robots are in microscale, and they can swim inside a fluidic environment with a low Reynolds number. In relation to microrobotics, mimicry of bacteria flagella, sperm flagella, cilia, and fish are significant. Due to the fact that these biological matters consist of different propulsion mechanisms, the effect of various parameters was investigated in the last decade and the review presents a summary that enhances understanding of the working principle of propulsion mechanisms. In addition, the effect of different parameters on the various speeds of the existing microrobots was analyzed to identify their trends. So, the swimming speeds of the microrobots show an upward trend with increasing body length, frequency, magnetic flux density, and helix angle. Microfabrication techniques play a significant role in the microscale because the device designs are highly dependent on the availability of the techniques. The presented microrobots were manufactured by 3D/4D photolithography and rapid prototyping techniques. Proper materials enable effective fabrication of microrobots using the mentioned techniques. Therefore, magnetically active material types, matrix materials, biocompatible and biodegradable materials are presented in this study. Utilizing biocompatible and biodegradable materials avoids adverse effects to the organs that could occur otherwise. In addition, magnetic field generation is significant for the propulsion of such microrobots. We conclude the review with an overview of the biomimicry of microrobots and magnetically actuated robot propulsion.
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This paper discusses an active droplet generation system, and the presented droplet generator successfully performs droplet generation using two fluid phases: continuous phase fluid and dispersed phase fluid. The performance of an active... more
This paper discusses an active droplet generation system, and the presented droplet generator successfully performs droplet generation using two fluid phases: continuous phase fluid and dispersed phase fluid. The performance of an active droplet generation system is analysed based on the droplet morphology using vision sensing and digital image processing. The proposed system in the study includes a droplet generator, camera module with image pre-processing and identification algorithm, and controller and control algorithm with a workstation computer. The overall system is able to control, sense, and analyse the generation of droplets. The main controller consists of a microcontroller, motor controller, voltage regulator, and power supply. Among the morphological features of droplets, the diameter is extracted from the images to observe the system performance. The MATLAB-based image processing algorithm consists of image acquisition, image enhancement, droplet identification, feature extraction, and analysis. RGB band filtering, thresholding, and opening are used in image pre-processing. After the image enhancement, droplet identification is performed by tracing the boundary of the droplets. The average droplet diameter varied from ~3.05 mm to ~4.04 mm in the experiments, and the average droplet diameter decrement presented a relationship of a second-order polynomial with the droplet generation time.
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This paper discusses the use of electrical circuit analogy for microfluidic channel networks in a Lab-on-a-Chip (LoC) device. LoC devices are comprised of microfluidic channels which serve various purposes such as mixing, droplet... more
This paper discusses the use of electrical circuit analogy for microfluidic channel networks in a Lab-on-a-Chip (LoC) device. LoC devices are comprised of microfluidic channels which serve various purposes such as mixing, droplet generation, and separation. As conventional fluid dynamic analysis for complex microfluidic geometries requires a considerable amount of computational time, the use of the electrical circuit analogy has become popular in recent years for microfluidic devices. By using Hagen-Poiseuille’s law and Ohm’s law analogies, the use of the electrical circuit analogy for different geometries with single phase and two-phase fluidic flow systems are discussed in the research. Both CFD and electrical circuit simulations are conducted and results are compared in this paper. It was identified that the electrical circuit analogy is suitable for the single-phase fluid phase flow behaviour, whereas the analogy is not suitable to analyse the multi-phase flows.
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This paper presents the design approach and development of a novel External Pipeline Robot (EPR) named ExPiRo with the capability of moving on linear segments of cylindrical structures with variable diameters in the range 100 mm to 130... more
This paper presents the design approach and development of a novel External Pipeline Robot (EPR) named ExPiRo with the capability of moving on linear segments of cylindrical structures with variable diameters in the range 100 mm to 130 mm. The robot has a passive pipe clutching mechanism created from two parallelogram four-bar linkages. The designed robot can carry payloads up to 2.2 kg. The ExPiRo prototype demonstrated the desired ability to travel on a varying diameter pipe during testing. A control system for position controlling of the robot within the pipeline is also proposed. An ADAMS-MATLAB co-simulation is conducted to evaluate the performance of the proposed control system. The control system demonstrated significant stability in reaching different goal positions.
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With advancements in related sub-fields, research on photomicrography in life science is emerging and this is a review on its application towards human full blood count testing which is a primary test in medical practices. For a prolonged... more
With advancements in related sub-fields, research on photomicrography in life science is emerging and this is a review on its application towards human full blood count testing which is a primary test in medical practices. For a prolonged period of time, analysis of blood samples is the basis for bio medical observations of living creatures. Cell size, shape, constituents, count, ratios are few of the features identified using DIP based analysis and these features provide an overview of the state of human body which is important in identifying present medical conditions and indicating possible future complications. In addition, functionality of the immune system is observed using results of blood tests. In FBC tests, identification of different blood cell types and counting the number of cells of each type is required to obtain results. Literature discuss various techniques and methods and this article presents an insightful review on human blood cell morphology, photomicrography, d...
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Aiming the non-stationary characteristics of underwater noise signal, an underwater noise signal processing method based on LMD envelope spectrum is proposed in this paper, which uses the local mean decomposition (LMD) on the underwater... more
Aiming the non-stationary characteristics of underwater noise signal, an underwater noise signal processing method based on LMD envelope spectrum is proposed in this paper, which uses the local mean decomposition (LMD) on the underwater noise signal, and product function (PF) components of some instantaneous frequencies with physical meaning are obtained. Then, the kurtosis of each PF component is calculated, and the components that contain more information of underwater target noise are selected as sensitive components according to kurtosis feature. After that, the wavelet packet decomposition and reconstruction are used for these sensitive PF components, and then the Hilbert transform is used to find the envelope spectrum of the reconstructed sensitive PF components. Through the processing and analysis of the signal collected by the experiment at the wharf, and compared with the EMD decomposition method, the experimental results show that: (1) When the underwater noise signal is p...
Research Interests:
This paper discusses the use of electrical circuit analogy for microfluidic channel networks in a Lab-on-a-Chip (LoC) device. LoC devices are comprised of microfluidic channels which serve various purposes such as mixing, droplet... more
This paper discusses the use of electrical circuit analogy for microfluidic channel networks in a Lab-on-a-Chip (LoC) device. LoC devices are comprised of microfluidic channels which serve various purposes such as mixing, droplet generation, and separation. As conventional fluid dynamic analysis for complex microfluidic geometries requires a considerable amount of computational time, the use of the electrical circuit analogy has become popular in recent years for microfluidic devices. By using Hagen-Poiseuille’s law and Ohm’s law analogies, the use of the electrical circuit analogy for different geometries with single phase and two-phase fluidic flow systems are discussed in the research. Both CFD and electrical circuit simulations are conducted and results are compared in this paper. It was identified that the electrical circuit analogy is suitable for the single-phase fluid phase flow behaviour, whereas the analogy is not suitable to analyse the multi-phase flows.
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Aiming the non-stationary characteristics of underwater noise signal, an underwater noise signal processing method based on LMD envelope spectrum is proposed in this paper, which uses the local mean decomposition (LMD) on the underwater... more
Aiming the non-stationary characteristics of underwater noise signal, an underwater noise signal processing method based on LMD envelope spectrum is proposed in this paper, which uses the local mean decomposition (LMD) on the underwater noise signal, and product function (PF) components of some instantaneous frequencies with physical meaning are obtained. Then, the kurtosis of each PF component is calculated, and the components that contain more information of underwater target noise are selected as sensitive components according to kurtosis feature. After that, the wavelet packet decomposition and reconstruction are used for these sensitive PF components, and then the Hilbert transform is used to find the envelope spectrum of the reconstructed sensitive PF components. Through the processing and analysis of the signal collected by the experiment at the wharf, and compared with the EMD decomposition method, the experimental results show that: (1) When the underwater noise signal is processed, the result of LMD decomposition is better than that of EMD decomposition. (2) The underwater noise signal processing method based on LMD envelope spectrum can process underwater noise signal effectively, and there is an obvious spectral line in the frequency range of target sound source.