The advantages and challenges of exosuits
Soft exosuits offer various advantages over rigid exoskeletal systems, such as reduced weight, enhanced variability in stiffness and force-to-weight ratios, and a design that concentrates mass at the centre of mass to minimise the moment of inertia at the extremities, they introduce significant challenges in their development and implementation. The requirement for these exosuits to incorporate soft structures and compliant control systems that align with the complex kinematics of human joints, alongside the capability to provide naturalistic walking assistance and to be discretely worn under clothing, necessitates a comprehensive, multidisciplinary research approach. Addressing these challenges, which span across neuroscience, biomechanics, robotic control, and ergonomics, is crucial for harnessing the full potential of soft exosuits in diverse applications such as industrial work, military operations, and clinical rehabilitation, thereby advancing the rapidly growing field of soft robotics.
A fundamentally new approach
Soft robotics has become one of the fastest-growing fields over the last decade, and the development of technologies related to the associated modelling, sensing, actuation, and control challenges has flourished as part of the field’s impetus. Soft robots have been demonstrated in diverse applications such as wearable devices, mobile or locomotive robots, as well as soft manipulators. Soft lower extremity exoskeletons, known as 'soft wearable robotics' (SWRs), are amongst the most challenging research topics and require multidisciplinary approaches involving diverse fields such as neuroscience, biomechanics, robot control, ergonomics, and others.
SWAG aims to explore a fundamentally new approach to engineering soft structures that omit fully rigid materials in favour of inflatable ones made from high-strength fabrics and films when manufacturing human-assistive exoskeletal devices targeting strain-prone segments of the human body (i.e. the lower body and core). Such soft wearable adaptive garments with actuation capabilities offer higher variable stiffness and force-to-weight ratios compared to other existing methods and simultaneously conform entirely to each joint’s intricate kinematics. Because of this, new design approaches can be used as building blocks to realise complete assistance for multi-degree-of-freedom joints, such as the ankle or hip, by adapting flexible and conforming motions achieved by continuum robot designs.
Addressing the comparative efficacy and integration challenges of soft exosuits in relation to their rigid counterparts constitutes a significant research problem within the field of robotics. Soft exosuits, distinguished by their lightweight construction, adjustable stiffness, and enhanced force-to-weight ratios, offer a paradigm shift in wearable assistive devices. By centralising mass at the body's centre of mass, these devices markedly reduce the moment of inertia at the limbs, thereby aligning more closely with the natural biomechanics of human motion. The incorporation of soft materials and compliant control strategies allows for an unprecedented conformity to the kinematics of individual joints, facilitating an assistance mode that closely mimics the physiological tension forces in muscles and tendons. This biomimetic approach not only augments the naturalism of assisted movements but also enables the exosuits to be discretely worn under clothing, significantly mitigating the psychological impediments associated with wearable robotics.
However, the transition from rigid to soft exoskeletal systems introduces a complex array of multidisciplinary challenges. The nuanced interplay between soft material dynamics, control algorithms, and human biomechanics necessitates innovative approaches in design and implementation. Furthermore, the effective integration of soft exosuits in real-world applications—spanning industrial labour, and therapeutic interventions—demands rigorous investigation into their durability, adaptability, and user interface. Thus, the research problem encompasses not only the engineering and material science aspects of soft exosuits but also extends to the domains of neuroscience, biomechanics, and ergonomics, underscoring the need for a comprehensive and interdisciplinary research strategy to unlock the full potential of soft robotic exosuits.
Transformative changes
SWAG aims to bring transformative changes across multiple sectors by enhancing human performance, mobility, and interactive experiences. This exosuit, distinguished by its capability to provide simultaneous active actuation to four different joints (lower back, hip, knee, ankle), is designed to cater to a wide audience outside of academia, including individuals with mobility impairments, professionals in physically demanding occupations, athletes, and users of virtual reality systems.
- Individuals with Mobility Impairments: SWAG aims to significantly improve the quality of life for people facing mobility challenges by offering motion assistance. This application can revolutionise rehabilitation processes and daily living activities, enabling individuals to achieve greater independence and mobility.
- Occupational Enhancement: In sectors where physical tasks are prevalent, such as manufacturing, construction, and logistics, SWAG can provide crucial support, reducing the risk of injuries and enhancing overall worker productivity and safety. By assisting with lifting, carrying, and repetitive movements, the exosuit can contribute to the sustainability of operations within these industries.
- Athletes and Physical Training: SWAG's potential as wellness training equipment introduces a new dimension to athletic training by providing resistive capabilities. This feature can be leveraged to enhance strength training, improve endurance, and aid in recovery processes, thereby elevating athletic performance.
- Virtual Reality Applications: Integrating SWAG with VR applications opens novel interactive and immersive experiences. By offering haptic feedback, the exosuit can make VR environments more realistic and engaging, finding applications in gaming, simulation-based training, and therapeutic scenarios.
BIC's role is integral to the system's distributed sensing and control implementation. BIC is leading the development of data acquisition and pre-processing, which includes both firmware and hardware. Furthermore, BIC supports activities such as tracking user intent and AI development, distributed low-level control, model-based real-time adaptive control, development of on-board electronics platforms, real-time EMG-driven musculoskeletal modelling, as well as the design of mechanical and software architectures. Additionally, BIC is involved in software integration and the evaluation of system performance.
Partners
- TWI Hellas
- Hellenic Mediterranean University
- Bendabl
- Universität Heidelberg
- Scuola Superiore Sant'Anna
- IUVO
- Eurecat
- Jožef Stefan Institute
- University of Twente
- Roessingh Research and Development
- University of Hertfordshire
- Imperial College London