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This article presents the design of a magnetic microactuator comprising soft magnetic material blocks and flexible beams. The modular layout of the proposed microactuator promotes scalability towards different microrobotic applications using low magnetic fields. The presented microactuator consists of three soft magnetic material (Ni-Fe 4750) blocks connected together via two Polydimethylsiloxane (PDMS) semi-circular beams. A detailed design approach is highlighted giving considerations toward compactness, range of motion and force characteristics of the actuator. The actuator displacement and force characteristics are approximately linear in the magnetic field strength range of 80-160 kA/m. It can achieve maximum displacements of 111.6 µm (at 160 kA/m) during extension and 10.7 µm (at 80 kA/m) during contraction under no-load condition. The maximum force output of the microactuator, computed through a contact simulation, was 404.3 nN at a magnetic field strength of 160 kA/m. The microactuator achieved stroke angles up to 18.4 in a study where the microactuator was integrated with a swimming microrobot executing rowing motion using an artificial appendage, providing insight into the capabilities of actuating untethered microrobots.

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, digital image processing of photomicrographs, feature extraction and classification, and recent advances. Integration of emerging technologies such as microfluidics, micro-electromechanical systems, and artificial intelligence based image processing algorithms and classifiers with cell sensing have enabled exploration of novel research directions in blood testing applications.

This work contributes to a novel method of manufacturing a Shape Memory Alloy (SMA) based spring actuators for Laparoscopic grippers. The actuator was manufactured using a novel fixturing method followed by a heat treatment process. Afterwards, the developed actuator samples were tested using Differential Scanning Calorimetry (DSC) for transformation temperature investigation and Energy-dispersive X-ray Spectroscopy (EDX) was performed to account for the elemental composition of the utilized SMA material. The characterized spring actuator element is coupled to a gripper manufactured by a combination of conventional manufacturing and rapid prototyping techniques. A testing apparatus was introduced which was used to evaluate the operation of the gripper. Finally, the sustainability in SMA based actuation technologies was highlighted using inherent properties of the SMA materials.

The study presents the design and fabrication process of a novel microfluidic active droplet generator and development of a controller to actuate the integrated micropumps. The proposed active droplet generator consists of a droplet generation geometry and two microfluidic pumps to control the flow rate of the continuous phase fluid and the dispersed phase fluid to generate a microflow towards the droplet generation geometry. The droplet generator is developed based on flow-focusing geometry. Proposed micropumps have a pump chamber and a reservoir. A layer by layer method is adapted in fabricating the active droplet generator in which Polymethyl Methacrylate (PMMA) is used as the material. A heat treating based bonding method is discussed in combining fabricated PMMA layers together. Piezoelectric transducer, which is used as the actuator, is made of Lead Zirconate Titanate (PZT) and integrated into the micropump geometry to produce the microflow. The developed controller is capable of providing a range of shapes, frequencies, and amplitudes for the input signal leading to successful operations of the active droplet generator.

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.

This paper presents development of a pipeline defect detection (PDD) system and designing main components of the system to reduce the risk of environmental pollution due to pipeline accidents. Main feature presented is a robotic system including a pipe navigation mechanism and a vision system. ExPIRo robot platform developed at the previous stage of the research is used as the moving mechanism for the robotic system with minor modifications. Vision system is developed by the integration of a camera module, a single board computer and a remote workstation. PDD system presented provides remote monitoring and analyzing features by utilizing the remote workstation for data storage. MATLAB-based image acquisition algorithm is performed on LATTEPANDA single board computer, whereas the defect identification algorithm is performed on HP Envy 6-1012TX Ultra-Book laptop. GUI developed for the system visualizes the stages of image analysis and displays result while updating the result of each image for defect identification purpose. External surface defects having significant appearance abnormalities are tested using the presented PDD system, images of pipe segments are captured, and defects are successfully identified.

Lab on a Chip (LOC) devices minimize, integrate, automate, and parallelize laboratory functions such as mixing, separation, and incubation on a single chip. Droplet generation is one key aspect in LOC devices which allows to conduct various chemical and biochemical assays enabling biological cell studies, high throughput drug development, and diagnostic screenings. This paper presents, modelling, simulation, and experimentation of an active droplet generator that is widely used in LOC devices. The model geometry used in this study was based on a flow focusing method of droplet generation. Droplet generation from the numerical simulations was observed within flow rate ratios ranging from 0.2 to 4 using optimised droplet contraction width of the generator model. Subsequently, a prototype droplet generator was designed and developed from Polymethyl Methacrylate (PMMA) material using a layer-based fabrication method. Based on the experimental setup presented here, the calculated ratios of flow rates obtained for different voltage values have shown that the formation of droplets occur between flow rate ratios of 1.04 and 4.74. In addition, morphological parameters of the droplet images extracted from a digital image processing algorithm show that the mean diameter of the droplets decreases with decreasing flow rate ratios.

This work introduces a novel method of integrating a force feedback system for a gripper actuated by a Shape Memory Alloy (SMA) spring actuator which is actuated by external heating. The targeted application of this gripper mechanism is to be used in a Minimally Invasive Surgical (MIS) tool since there is a need of miniaturization and enhancement of feedback to the surgeon. The SMA actuator and a test apparatus containing the gripper which is activated by hot and cold fluid sources was developed in this study. The actuator is operated by controlling the fluid temperature and flow rate through a customized multi-functional controller. The controller operates the opening and closing motion while maintaining the gripper force by controlling the flow rate of the fluid sources. The gripper force sensing was achieved through a strain gauge based sensing method. Finally, the force controlling performance of the system was evaluated.

Under this research, a novel tactile sensor has been developed using a conductive polymer-based sensing element. The incorporated sensing element is manufactured by polymer press moulding, where the compound is based on silicone rubber and has enhancements by silica and carbon black, with Silane-69 as the coupling agent. Characteristics of the sensing element have been observed using its sensitivity and range, where its results pose an inherent nonlinearity of conductive polymers. For the force scaling purpose, a novel 3D printed cylindrical arch spring structure was developed for this highly customizable tactile sensor by adopting commonly available ABSplus material in 3D printing technology. By considering critical dimensions of the structure, finite element analysis was carried out to achieve nearly optimized results. A special electrical routing arrangement was also designed to reduce the routing complexities. The optimized structure was fabricated using the 3D printing technology. A microcontroller-based signal conditioning circuit was introduced to the system for the purpose of acquiring data. The sensor has been tested up to the maximum load condition using a force indenter. This sensor has a maximum applicable range of 90 N with a maximum structural deflection of 4 mm. The sensor assembly weighs 155 g and the outer dimensions are 85 mm in diameter and 83 mm in height.

Background Transhumeral prostheses are worn by transhumeral amputees to replace the missing upper limb segment between shoulder and elbow. Prostheses should be able to function as a natural limb for the user to gain the full advantage of wearing a prosthesis. When performing reach-to-grasp and pointing motions by the upper limb, the hand is capable of adhering to a straight-line path with a bell-shaped velocity profile. Aim Aim was to develop a dynamic path-tracking method for transhumeral prostheses to gain the capability of adhering to a straight-line path. Method Proposed method uses model predictive controller (MPC) developed based on the kinematic model of the prosthesis. Moreover, a shoulder matcher is proposed to match actual shoulder pose with the predicted shoulder pose and to select the best joint angles for the prosthesis for a particular instance. Furthermore, the proposed method is capable of dynamically updating the path if the human performs shoulder motions, which are not as planned by the MPC. Results Several experiments are conducted to validate the proposed method. The proposed method is capable of taking a straight-line path similar to a natural human. Conclusion This paper proposed a dynamic path-tracking method based on a model predictive controller. The proposed method is capable of taking the prosthetic hand on a straight-line path, which is similar to a path taken by a natural human hand.

A shape memory alloy (SMA)-based spring actuated gripper (SAG) was designed and developed for facilitating minimally invasive surgeries (MIS). Specifically the research consists of design and development of a SMA spring which acts as the actuator for the gripper. A novel mechanism was also developed to transfer the actuator force to the gripper jaws. Further, the actuator force was characterized by a testing apparatus which uses a full-bridge load cell as the force sensing element. The activation temperature of the SMA actuator was obtained by performing differential scanning calorimetry (DSC) tests on the samples.