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Electrical machines are the central components of many energy conversion systems. Developing the performance of these devices is critical for improved energy management in our society. A new generation of electrical equipment has been enabled by the recent development of additive manufacturing (AM) technologies. This research takes advantage of the greater design freedom given by such approaches to enhance the heat dissipation qualities of the machines in two aspects. Firstly, varying-thickness windings fill up the available space leading to a reduced winding resistance so that the Joule losses can be decreased. Secondly, a novel design of a multi-functional 3D-printed winding is presented. This innovative design accomplishes self-cooling capabilities by including heat sinks into the end-winding. It is achieved by extending the heads of the coils from each turn extremity, creating heat sinks as part of the winding itself. The heat can be extracted directly from the coils to the ambient environment without intermediate pieces. The suggested approaches reduce heat generation and improve heat transmission, allowing for a higher input current. This results in machines with larger power densities for the same volume of permanent magnets while keeping passive cooling. We study a linear coreless permanent magnet machine to explore the concept. Nevertheless, this approach can be applied to different types of electrical machines possibly accommodating other cooling methods.

Magnetic manipulation is a method used for biomedical applications to remotely control micro-robots in a contactless manner. The electromagnet manipulator should control a magnetic field with 3 degrees of freedom inside a region of interest. In various case studies, this field results from the superposition of three decoupled uniform magnetic fields. Each of them is individually generated by a different pair of Helmholtz coils. Such an arrangement requires the pairs to be nested within each other, inevitably reducing the working area’s size and degrading the whole system’s performance and integration. The proposed work aims to design a novel electromagnetic manipulator with the help of computational design, to explore beyond the Helmholtz coils arrangement. A topology optimization framework is developed for this purpose. It investigates the distribution of coils that achieves the best field uniformity for a fixed footprint while keeping the different degrees of freedom balanced.

Coreless electric motors are gaining interest from the community as they have a larger power-to-weight ratio and higher efficiency. The absence of iron slots leaves the winding space unobstructed. It enables the geometry of the coils to be skewed to overlap with their neighbors. This work proposes a topology optimization method to design 3D-printed motor windings aiming for coreless electrical machines with higher motor-constant. A multi-coil interpolation scheme is proposed to design a single coil while accounting for packing with the other ones constituting the winding, without requiring assumptions on the shape or position of the coil. The standard 2-D topology optimization is extended to a 2.5-D one so as to provide more freedom on the achievable geometries while keeping a reasonable computational time. The developed computational design tool generated a novel motor winding with high performance.

This article proposes a swirling actuator that uses the electromagnetic radial force and mechanical gears to generate rotational torque. The proposed actuator generates a rotating radial force between an inner stator and a swirler. The gears on the swirler and outer rotor convert the circular motion of the swirler to low-speed rotor rotation. Thus, the proposed actuator is aimed at low-speed high-torque applications. In this study, the air-gap radial flux density and electromagnetic radial force are investigated analytically and verified through finite-element analysis. The static radial force and output torque are measured in a prototype of the actuator. The system efficiency and the gear efficiency are evaluated. A peak torque density of 27 Nm/L with a small volume of 0.16 L is realized in the prototype.

The modern world is heavily reliant on electromagnetic devices to convert mechanical energy into electrical energy and vice versa. These devices are fundamental to powering our society, and the growing need for automated production lines and electrified transportation is driving the demand for even more advanced electromagnetic actuators. A critical component of these devices is the electromagnetic coil, typically constructed from copper wire wound into simple shapes. Over the years, extensive research and industrial development have led to a deep understanding of this technology. Nevertheless, innovation is needed to improve upon state-of-the-art or to access applications with harsher requirements. In this thesis, we propose using additive manufacturing techniques to fabricate electromagnetic coils, which eliminates geometric limitations and opens up new design possibilities. We also utilize computational design methods, which reformulate the design problem as an optimization one. These tools generate complex shapes belonging to a broader solution set than the one accessible by a human designer. The implemented method (topology optimization) investigates the ideal distribution of material in space. It first demonstrates the possibility of generating coils within a 2-D plane. This framework is expanded to consider the packing of multiple coils constituting motor windings without a-priori knowledge of their position or shape. A 2.5-D approach is formulated to design overlapping coils while maintaining a low computational cost. A 3-D analysis is also explored for designing coils with different functions in an electromagnet manipulator. The generated designs exhibit significantly improved electromagnetic performance, such as a motor constant increased by 17% or regions with uniform magnetic field 7 times larger than the references. The feasibility of additively manufacturing electromagnetic coils is examined through a study case of a linear motor with a reference coil topology. Innovative design features, such as tracks with an evolving cross-section and "completed" linear windings, are proposed to fully harvest the design freedom provided by additive manufacturing. Additionally, we propose the concept of multi-functional windings, integrating heat sinks within the electromagnetic coils for improved efficiency and self-cooling capabilities. This results in the possibility of increasing the motor force by 17.3% without increasing the volume of permanent magnets. Prototypes of various coil geometries are fabricated and tested. Overall, this thesis lays the foundation for a new generation of electromagnetic devices with improved performance through the combination of computational design methods and additive manufacturing technologies.

This work presents the electromagnetic design of a 3D-printed winding for a coreless linear motor. The key geometric parameters are optimized with motor constant as the objective. The optimization is applied to two types of coil layouts. An increase of the motor constant up to +26% is observed for the optimized coils compared with the original ones. Several units of the two types of coils are 3D-printed in aluminum alloy and electrically characterized. A glider prototype is assembled and ready for additional tests evaluating experimentally the motor constant in order to be compared to simulations.

Coreless electric motors are gaining interest from the community as they have a larger power-to-weight ratio and a larger efficiency. The absence of iron slots leaves the winding space unobstructed. This enables the geometry of the coils to be skewed to overlap with their neighbors. Such arrangement provides better motor constant. This work proposes to establish some groundwork for the topology optimization of overlapping winding in multi-phase coreless motors. A 2.5D formulation of the density-based approach is proposed to enable the designed coils to span over two layers and spatially overlap with their neighbors, while keeping a limited computational cost. A novel interpolation scheme is also proposed to account for multi-phase winding while only designing one phase.

Soft Magnetic Composites (SMCs) have huge application potential in electrical devices. With the development of additive manufacturing (AM), the properties of SMCs can be boosted. It is therefore required an optimization algorithm to design SMCs considering the AM capacity. Since the magnetic and loss properties of SMCs are highly sensitive to the shape evolution of the components, we introduce a topology optimization approach with integer programming. At each iteration, the components of the composite are determined with crisp boundary. This optimization algorithm converges rapidly because of the topology gradient and the optimal topology is reached.

Magnetic manipulation is a method used for biomedical applications to remotely control micro-robots in a contactless manner. The electromagnet manipulator should control a magnetic field with 3 degrees of freedom inside a region of interest. In various case studies, this field is the result of the superposition of three decoupled uniform magnetic fields. Each of them is individually generated by a different pair of Helmholtz coils. Such arrangement requires the pairs to be nested within each other, inevitably reducing the size of the working area, degrading the performance and the integration of the whole system. The proposed work aims to design a novel electromagnetic manipulator with the help of computational design, to explore beyond the Helmholtz coils arrangement. A topology optimization framework is developed for this purpose. It investigates the distribution of coils that achieves the largest working area, while keeping the different degrees of freedom balanced.

Soft Magnetic Composites (SMCs) possess promising electromagnetic characteristics and attract intense research and application interest in the engineering community. Fabrication of composites with customized architecture is feasible due to the recent advances in additive manufacturing techniques. The systematic progress of computational optimization has opened up the possibility of devising such structures. This article aims to optimally design the shape of inclusion in SMCs. Their advantages are potentially high magnetic permeability and low eddy current losses at a certain volume fraction of the iron material. The shape derivative is calculated for the descent direction and the level-set method is used to evolve the domain. We implement the algorithm in two-dimensional space considering the linear magnetic behavior of iron. In this article, the objective is the effective magnetic permeability at a given volume fraction of inclusion for magnetostatics.

Constipation is an area of concern in people’s health. Consequently, health care practitioners recommend lifestyle changes including increasing fiber intake and exercise. This study examined the effect of pea hull fiber (PHF) on loperamide-induced constipation in rats. The rats were fed either a vehicle diet or a diet enriched with PHF. The groups were divided into either a saline or loperamide injection to induce sub-acute constipation. Fecal Pellet Output (FPO) was measured for 3 days. In the saline-treated rats, PHF increased wet and dry fecal weights on day 1 and 2, and increased FPO on day 2 compared to the saline-treated rats on the vehicle diet. In the loperamide model, PHF increased FPO, had higher wet and dry fecal weights on day 1 compared to the loperamide-treated vehicle diet rats. Addition of PHF into the diet may help improve intestinal transit in a loperamide-induced constipation rat model.

An imbalance of the gut microbiota ("dysbiosis") is associated with numerous chronic diseases, and its modulation is a promising novel therapeutic approach. Dietary supplementation with soluble fiber is one of several proposed modulation strategies. This study aims at confirming the impact of the resistant dextrin NUTRIOSE (RD), a soluble fiber with demonstrated beneficial health effects, on the gut microbiota of healthy individuals.Fifty healthy women are enrolled and supplemented daily with either RD (n = 24) or a control product (n = 26) during 6 weeks. Characterization of the fecal metagenome with shotgun sequencing reveals that RD intake dramatically increases the abundance of the commensal bacterium Parabacteroides distasonis. Furthermore, presence in metagenomes of accessory genes from P. distasonis, coding for susCD (a starch-binding membrane protein complex) is associated with a greater increase of the species. This suggests that response to RD might be strain-dependent.Supplementation with RD can be used to specifically increase P. distasonis in gut microbiota of healthy women. The magnitude of the response may be associated with fiber-metabolizing capabilities of strains carried by subjects. Further research will seek to confirm that P. distasonis directly modulates the clinical effects observed in other studies.

Touch-screens are the most relevant interface in the context of human-computer interaction. Moreover, they are widely used as interaction means for digital musical instruments, where a complex action-perception loop is involved in the user experience. This is why reestablishing a rich vibrotactile feedback is of key importance for improving the quality of the user's interaction. To the knowledge of the authors, this paper presents the first experiments with Generative Adversarial Networks (GANs) to generate time-reversed signals that can be used to create localized vibrotactile feedback over a rigid surface. The generated signals are sent into an experimental setup and a vibration scan is carried out. A localized peak generated with a signal synthesized by the trained GAN model is observed and studied. Later, different metrics are proposed to evaluate the quality of the generated samples and the obtained localized peak. Finally, a preliminary evaluation of the feasibility of this approach to generate localized vibrations in the range of 200 - 300 Hz for touch -screen applications is discussed.

Background. Carotenoids and docosahexaenoic acid (DHA) were identified as essential components for eye health and are both naturally present in eggs. Objective. We aimed to evaluate the effect of the daily consumption of two eggs enriched with lutein/zeaxanthin and DHA on macular pigment optical density (MPOD) and on circulating xanthophyll and fatty acid concentrations in healthy participants. Methods. Ninety-nine healthy volunteers consumed either two standard eggs or two enriched eggs per day for 4 months. MPOD was measured at baseline (V0) and at follow-up (V4) using a modified confocal scanning laser ophthalmoscope (primary outcome). Blood samples were collected to determine total plasma and lipoprotein fatty acids and lutein/zeaxanthin compositions at V0 and V4 (secondary outcomes). Results. A slight but significant increase in MPOD was observed for all study participants consuming two eggs per day for 4 months at all eccentricities (0.5°, 1°, 2°, and 4°). Plasma and lipoprotein lutein, zeaxanthin, and DHA concentrations significantly increased in both groups but were greater in the enriched group (for the enriched group (V0 vs. V4): lutein, 167 vs. 369 ng/mL, zeaxanthin, 17.7 vs. 29.2 ng/mL, DHA, 1.89 vs. 2.56% of total fatty acids). Interestingly, lutein from high-density lipoprotein (HDL) was strongly correlated with MPOD at 0.5 and 1° eccentricities (rho = 0.385, p = 0.008, and rho = 0.461, p = 0.001, respectively). Conclusions. MPOD was slightly increased in both groups. Lutein, zeaxanthin, and DHA plasma concentrations were strongly enhanced in the enriched group compared with the standard group. A significant correlation was found between MPOD level and lutein concentration in HDL.