Hugo Rodrigue

This study proposes a new type of series elastic actuator (SEA) utilizing a mixture of air and water. Instead of simply mixing air and water, a control method for its output force based on piston position control is suggested using the stiffness model of the mixture. The actuator is driven by the pressure generated when a stiff linear actuator comp...

To make robots more human-like and safer to use around humans, artificial muscles exhibiting compliance have gained significant attention from researchers. However, despite having excellent performance, pneumatic artificial muscles (PAMs) have failed to gain significant traction in commercial mobile applications due to their requirement to be tethe...

For mechanical systems where a human–machine interface or interaction is necessary, it is important to consider physical safety. In cases where robots and humans must coexist, these robots must have actuation that is inherently compliant to absorb physical impacts. However, these compliant actuators must possess high performance that is comparable...

Shape memory alloys (SMAs) are smart materials that are widely used to create intelligent devices because of their high energy density, actuation strain, and biocompatibility characteristics. Given their unique properties, SMAs have been found to have significant potential for implementation in many emerging applications in mobile robots, robotic h...

Inspection robots that can be used to inspect man-made structures have significant potential for industrial applications, but existing soft robots are not well suited for the exploration of complex metallic structures with many obstacles. This paper proposes a soft climbing robot well suited for such conditions as the robot uses feet with a control...

Octopuses can use as few as a single sucker to grab and hold onto objects as each sucker creates its own vacuum pressure using their individual muscles. Man-made suction arrays using vacuum pressure need mechanical solutions such as check valves for every suction cup, or they need to compensate for air leakage using heavy high flow pumps. The syste...

The performance of pneumatic artificial muscles (PAMs) depends in large part on the fluidic hardware used to add and remove air from their volume. A complete fluidic system usually contains tubing, pneumatic regulators, pneumatic valves, and pneumatic pumps. However, for most PAMs, the performance of the actuator depends on how fast air can be take...

The performance of soft robots depends in large part on the actuation performance of the soft actuators used to drive them, and those making use of fluidic actuation have gained the most traction in the form of pneumatic artificial muscles (PAMs). These PAMs make use of the change in volume of a structure through pressurization of their volume to p...

The human forearm produces torsional motions that are essential in daily activities such as opening doors or containers. It has a large range of motion (ROM), can produce large torques, can move bidirectionally, and can stiffen at will. Implementing such motions in a rigid robotic manipulator is easy due to the inherently rotational motions of elec...

Soft optoelectronic sensors capable of multimodal sensing have high repeatability, which makes them an attractive choice for applications requiring deformable sensors. A weakness of these sensors is the constant supply of electrical power input required to pass the light signal through their core, which can lead to excessive power requirements for...

Existing pneumatic artificial muscles generally rely on the use of either positive or negative pressure for actuation with each having their own advantages and disadvantages. Herein, a hyperbaric vacuum‐based artificial muscle (Hyper‐VAM) making use of both positive and negative pressures almost interchangeably is described. This is done by placing...

Soft exosuits used for supporting human muscle strength must be lightweight and wearable. Shape memory alloy (SMA) spring-based fabric muscles (SFM) are light and flexible, making them suitable for soft and shape-conformable exosuits. However, SFMs have a slow actuation speed owing to the slow cooling rate of the SMA spring. This paper proposes a f...

The development of soft actuators and robots has spurred interest in human-friendly robots and devices that can operate in proximity with living things. Researchers have used soft actuators to drive hybrid soft/rigid mechanical platforms with multiple degrees of freedom (DOFs) that are both compliant and produce precise motions. However, the additi...

The manufacturing method of soft pneumatic robots affects their ability to maintain their impermeability when pressurized. Pressurizing them beyond their limits results in leaks or ruptures of the structure. Increasing their size simultaneously increases the tension forces within their structure and reduces their ability to withstand the pressures...

This letter introduces a simultaneous positive and negative pressure controller for a pneumatic pump. For precise position or force control of the pneumatic soft actuator, the pressure from the source has to be regulated. When the positive and negative pressures are regulated, coupled dynamics caused by the pressure change affect the controller per...

Twisted and coiled actuators (TCAs), which are light but capable of producing significant power, were developed in recent times. After their introduction, there have been numerous improvements in performance, including development of techniques such as actuation strain and heating methods. However, the development of robots using TCA is still in it...

Linear brakes are devices used to restrict relative linear motions between two points. The use of soft robotic technology has enabled the fabrication of lightweight linear brakes making use of frictional forces generated by a vacuum on jamming layers. This kind of device has significant potential for wearable devices as they are lightweight yet pro...

The manufacturing and assembly of soft actuators may seem like a straightforward affair, but various tools, equipment and specific know-how are required to build these actuators. Assembling them into soft robots can sometimes lead to numerous difficulties and often requires permanent assemblies of the components. Similarly, minimizing the number of...

Upper limb exosuits (ULEs) are wearable robots that can assist arms to lift or support an object. However, heavy wearable equipment often interferes with the free movement of a person's arms, which have a wide range of motions. This article presents the design and manufacturing processes for a ULE that does not restrict the range of motion of the p...

Kirigami structures are human-made structures that enable the fabrication of stretchable structures from materials with limited stretching properties through the geometrical re-orientation of their features. But these structures are generally complex in shape with many edges which makes their precise fabrication difficult without the use of enginee...

Recently, owing to the significant advancement in the field of soft robots, various studies have been conducted on soft actuators. Among the several soft actuators, the double helix twisted and coiled actuator (DTCA), which is fabricated by coiling spandex and nylon under twisted conditions, exhibits considerable performance in terms of large contr...

Most soft actuators producing joint-like deformations rely on the expansion of materials or on the use of multiple chambers in equilibrium while requiring additional structures for inter-connecting the joints. This paper introduces a new soft pneumatic actuator where a constriction placed on an inflatable tube allows the tube to bend around the con...

In this article, a novel actuator called armor-based stable force pneumatic artificial muscle (AS-PAM) is presented. AS-PAM has a sealed chamber made of polygonal parts and film, which helps the actuator to be lightweight (∼100 g) and achieve a large contraction ratio (>60%). It has an armor and a constraint to guide its motion, which keeps its for...

The use of soft robots to interact with soft, fragile, and even living things has spurred interest in the development of soft robotic systems that can deform and adapt themselves to their environment through their inherent compliance. Current soft pneumatic actuator concepts require significant redesign to be repurposed from one function to another...

Most soft pneumatic actuators for producing bending actuation have made use of either positive or negative pressure and adjusted their design in consequence. In the proposed paper, a novel soft bending actuator using combined positive and negative pressures (PNP) where the bending force of a negative pressure actuator and a positive pressure actuat...

This paper introduces the addition of torsional pre-strain into the manufacturing process of shape memory alloy (SMA) springs to form torsionally pre-strained SMA (TPSMA) springs. These springs have higher performance at the same power input for the same loads and same coil dimensions as regular SMA springs. A modified thermoconstitutive model was...

Most soft pneumatic actuators require large pressures to realize their full deformations, have a non-negligible weight from their polymeric structures and have limited bending angles. In this work, a new soft pneumatic actuator utilizing anisotropic expansion of a pocket made from two different films is presented. This actuator is capable of bendin...

Shape memory alloy (SMA) wire-based soft actuators have had their performance limited by the small stroke of the SMA wire embedded within the polymeric matrix. This intrinsically links the bending angle and bending force in a way that made SMA-based soft grippers have relatively poor performance versus other types of soft actuators. In this work, t...

Soft pneumatic actuators using either pressurized air or vacuum pressure are the soft actuators with the most potential for real-life applications, but their energy efficiency has not been studied in much detail. In this work, a model-based method is presented that can predict the energy efficiency of origami-based vacuum pneumatic artificial muscl...

Soft robotics and actuators are becoming increasingly popular with diverse applications; their compliant structures and smooth deformations, which give rise to its softness, offer inherent safety to humans. This paper introduces the design of a twisting soft actuator based on pleated films that is inspired by the design of composite structures and...

Soft linear actuators (SLAs) make linear displacement by shrinkage and relaxation like skeletal muscles, so they can be called as artificial skeletal muscles (ASMs). They deform their body to create displacement. However, the restoring force generated by the deformation of their soft body reduces the force available from the SLA. This actuation str...

Shape memory alloy (SMA)-based soft actuators and grippers have generally used SMA wires due to design restrictions, limited actuation force and poor cooling performance of SMA springs. This work demonstrates that SMA springs can be used for high performance soft actuation by positioning them externally as a tendon with the force transmitted to the...

The performance of soft linear actuators will determine the capabilities of future soft robots, and any actuator that can produce larger deformations and forces with a low weight and using lower pressures could potentially become ubiquitous in the field. In this work, the design of paired pouch motors that can produce a maximum contraction ratio of...

A novel linear actuator called origami-based vacuum pneumatic artificial muscle (OV-PAM) is proposed in this study that can produce large forces (>400 N) with a contraction ratio >90% of the active length of the actuator. Moreover, some of the designs presented in this article can lift large loads with large contraction ratios at extremely low vacu...

This paper introduces a fabrication method and properties of newly developed Twisted and Coiled soft Actuator (TCA) from nylon and spandex. The TCA, a thermally driven actuator, is one of the promising soft actuators that shows considerable strain compared to the others. Typically, TCA is fabricated from single polymer fiber such as the spandex and...

Modular assembly is a widely-used strategy for fabricating diverse structures and robots, and more recently also for producing complex soft structures and machines. This work introduces a modular assembly method for soft deployable structures composed of identical soft deployable modules using embedded magnetic elements for the rapid assembly and d...

The performance of shape-memory alloy (SMA)-based soft actuators depends largely on the configuration of the cross-section of the actuator. A shape memory alloy-based curved bending actuator manufactured by double casting is introduced in this work. Curved actuators are capable of larger maximum bending angles with the same cross-section configurat...

The one-dimensional deformation of shape memory alloy (SMA) wires and springs can be implemented into different types of functional structures with three-dimensional deformations. These structures can be classified based on the type of structure and how the SMA element has been implemented into the following categories: rigid mechanical joints, sem...

The beam steering mechanism has been a key element for various applications ranging from sensing and imaging to solar tracking systems. However, conventional beam steering systems are bulky and complex and present significant challenges for scaling up. This work introduces the use of soft deployable reflectors combining a soft deployable structure...

This paper presents a biomimetic turtle flipper actuator consisting of a shape memory alloy composite structure for implementation in a turtle-inspired autonomous underwater vehicle. Based on the analysis of the Chelonia mydas, the flipper actuator was divided into three segments containing a scaffold structure fabricated using a 3D printer. Accord...

Morphing technology is inspired by biological motion for implementation in missions in a variety of areas without shape-change device. This study investigates the aerodynamic performance of a self-contained morphing winglet for an unmanned aerial vehicle (UAV) that mimics the wing-tip feathers of gliding birds. A smart soft composite (SSC), formed...

Manufacturing paradigms have historically been shaped by social, economic, and technological aspect, including limitations and needs. Design for manufacturing (DFM) has been the main paradigm for last three decades since design is defined by the limitations of available manufacturing processes. Since reducing the time required for the development o...

Deployable structure composed of smart materials based actuators can reconcile its inherently conflicting requirements of low mass, good shape adaptability, and high load-bearing capability. This work describes the fabrication of deployable structures using smart soft composite actuators combining a soft matrix with variable stiffness properties an...

Shape Memory Alloy (SMA) materials are widely used as an actuating source for bending actuators due to their high power density. However, due to the slow actuation speed of SMAs, there are limitations in their range of possible applications. This paper proposes a smart soft composite (SSC) actuator capable of fast bending actuation with large defor...

The design space for morphing wings is incredibly broad and allows for a wide range of improvements versus fixed wing aircrafts such that each type of morphing can be useful for different purposes. This work introduces a novel concept for a twist morphing wing segment where only a segment of the wing is actuated which causes a rotation of the tip o...

A new manufacturing method for smart soft composite (SSC) actuators that consists of double casting a SSC actuator to produce an actuator with non-linear shape memory alloy (SMA) wire positioning is proposed. This method is used to manufacture a tube-shaped SSC actuator in which the SMA wires follow the curvature of the tube and is capable of pure-...

Recently, robots have become a topic of interest with regard to their functionality as they need to complete a large number of diverse tasks in a variety of environments. When using traditional mechanical components, many parts are needed to realize complex deformations, such as motors, hinges, and cranks. To produce complex deformations, this work...

The design of SMA-based soft actuators is often limited by the design of the molds used, and these limitations are even more pronounced for actuators with complex shape memory alloy (SMA) wire positioning such as SMA-based twisting soft actuators. This paper aims at developing new mold designs to enable new design possibilities for the fabrication...

Morphing structures making use of smart materials are considered to be a promising technology for the amelioration of the aerodynamic performance of land and air vehicles. In particular, soft morphing structures are capable of continuous curvilinear structural deformation upon actuation without discrete sections that generate aerodynamic losses. In...

Soft morphing robotics making use of smart material and based on biomimetic principles are capable of continuous locomotion in harmony with its environment. Since these robots do not use traditional mechanical components, they can be built to be light weight and capable of a diverse range of locomotion. This paper illustrates a flexible smart phone...

A soft-bodied robot made of smart soft composite with inchworm-inspired locomotion capable of both two-way linear and turning movement has been proposed, developed, and tested. The robot was divided into three functional parts based on the different functions of the inchworm: the body, the back foot, and the front foot. Shape memory alloy wires wer...

Automotive wings are considered to be aerodynamic devices which have a significant effect on the driving, braking and cornering performances by influencing the flow of fluids around the vehicle without changing the weight of the vehicle. The wings have developed from having a fixed shape to multi-sectional wings in order to amplify the advantages o...

This article introduces a novel design for a soft morphing actuator capable of pure twisting motion through a pair of shape memory alloy wires embedded in a polydimethylsiloxane matrix at constant and opposite eccentricity across the cross section in opposite directions. This report introduces the design of the actuator, the manufacturing method, a...

This paper introduces a novel geometry for a pure-twisting soft morphing actuator that improves the stability of the actuator and allows it to obtain a larger twisting angle. The smart soft composite (SSC) actuator uses pair of NiTi shape memory alloy (SMA) wires embedded in a cross-shaped polydimethylsiloxane (PDMS) matrix at constant and opposite...

Les méthodologies de Design for Assembly et de Design for Manufacturing visent à rendre les produits plus faciles à fabriquer et à assembler en se basant sur les caractéristiques des procédés actuels de fabrication, toutefois ces caractéristiques ne s'appliquent plus lorsqu'on prend en compte les nouvelles capacités de la Fabrication Additive. Cet...

RÉSUMÉ La fabrication rapide est un procédé de fabrication dont le marché est en expansion rapide. Ce procédé de fabrication présente de nouvelles possibilités de fabrication révolutionnaires, telle la possibilité de créer des formes plus complexes et la possibilité de fabriquer des pièces composées de plusieurs matériaux. De plus, avec les procédé...