Inspired by the compliance found in many organisms, soft robots are made almost entirely out of flexible, soft material, making them suitable for applications in uncertain, dynamic task environments, including safe human-robot interactions. Their intrinsic compliance absorbs shocks and protects them against mechanical impacts. However, the soft materials used for their construction are highly susceptible to damage, such as cuts and perforations caused by sharp objects present in the uncontrolled and unpredictable environments they operate in. In this research, we propose to construct soft robotics entirely out of self-healing elastomers. On the basis of healing capacities found in nature, these polymers are given the ability to heal microscopic and macroscopic damage. Diels-Alder polymers, being thermoreversible covalent networks, were used to develop three applications of self-healing soft pneumatic actuators (a soft gripper, a soft hand, and artificial muscles). Soft pneumatic actuators commonly experience perforations and leaks due to excessive pressures or wear during operation. All three prototypes were designed using finite element modeling and mechanically characterized. The manufacturing method of the actuators exploits the self-healing behavior of the materials, which can be recycled. Realistic macroscopic damage could be healed entirely using a mild heat treatment. At the location of the scar, no weak spots were created, and the full performance of the actuators was nearly completely recovered after healing. 

We introduce damage intelligent soft-bodied systems via a network of self-healing light guides for dynamic sensing (SHeaLDS). Exploiting the intrinsic damage resilience of light propagation in an optical waveguide, in combination with a tough, transparent, and autonomously self-healing polyurethane urea elastomer, SHeaLDS enables damage resilient and intelligent robots by self-healing cuts as well as detecting this damage and controlling the robot’s actions accordingly. With optimized material and structural design for hyperelastic deformation of the robot and autonomous self-healing capacity, SHeaLDS provides reliable dynamic sensing at large strains (ε = 140%) with no drift or hysteresis, is resistant to punctures, and self-heals from cuts at room temperature with no external intervention. As a demonstration of utility, a soft quadruped protected by SHeaLDS detects and self-heals from extreme damage (e.g., six cuts on one leg) in 1 min and monitors and adapts its gait based on the damage condition autonomously through feedback control. 

Mimicking nature's self-healing ability has always been desired in science, especially when devices accumulate damage over time with performance, including the loss of function due to deterioration. SHAP (Self-Healing AETA([2-(acryloyloxy)ethyl]trimethylammonium chloride)-based Polymer), a hydrogel with autonomous self-healing ability that can be applied for the development of a pneumatic artificial muscle, is presented here. Unlike other self-healing hydrogels, SHAP does not require any external stimulus to self-heal and it presents outstanding anti-drying properties. Few-layer graphene is also incorporated into the polymer network of the hydrogel in order to study the possible influence that the nanomaterial has on the properties of the scaffolds. The mechanical behavior and the self-healing abilities of the resulting hydrogels are analyzed. Moreover, the mechanism of self-healing is discussed in terms of experimental results and theoretical calculations. The data suggest a mechanism based on strong hydrogen-bonding interactions between the water molecules that remain inside SHAP, which keeps the material wet and soft under ambient conditions. Finally, the development of a SHAP-based artificial muscle is presented. The results show good performance of the healed artificial muscles after damage, even with healing periods as short as 10 minutes. 

Self-healing polymers can address the damage susceptibility in soft robotics. However, in most cases, their healing requires a heat stimulus, provided by an external device. This letter presents a self-healing soft actuator with an integrated healable flexible heater, functioning as the stimuli-providing system. The actuator is constructed out of thermoreversible elastomers that are crosslinked by the Diels-Alder (DA) reaction, which provides the healing ability. The heater is manufactured from a DA-based composite network filled with 20 wt% carbon black to provide electrically conductive properties for resistive Joule heating. The flexibility of the heater does not compromise the actuator performance upon integration and the self-healing properties of both heater and actuator allow for damage repair. This includes very large damages, as both heater and actuator can recover (near 100%) from being cut completely in two pieces, using Joule heating at 90°C with a bias voltage of about 30 V. The embedded heater avoids the need for external intervention in the healing process, and provides healing quality assessment and a healing on-demand mechanism, paving the way for an optimum healing solution of damage resilient soft robots that require heat as a healing stimulus. 

Self-healing sensors have the potential to increase the lifespan of existing sensing technologies, especially in soft robotic and wearable applications. Furthermore, they could bestow additional functionality to the sensing system because of their self-healing ability. This paper presents the design for a self-healing sensor that can be used for damage detection and localization in a continuous manner. The soft sensor can recover full functionality almost instantaneously at room temperature, making the healing process fully autonomous. The working principle of the sensor is based on the measurement of air pressure inside enclosed chambers, making the fabrication and the modeling of the sensors easy. We characterize the force sensing abilities of the proposed sensor and perform damage detection and localization over a one-dimensional and two-dimensional surface using multilateration techniques. The proposed solution is highly scalable, easy-to-build, cheap and even applicable for multi-damage detection.

Self-healing soft robots show enormous potential to recover functional performance after healing the damages. However, healing in these systems is limited by the recontact of the fracture surfaces. This paper presents for the first time a shape memory alloy (SMA) wire-reinforced soft bending actuator made out of a castor oil-based self-healing polymer, with the incorporated ability to recover from large incisions via shape memory assisted healing. The integrated SMA wires serve three major purposes; (i) Large incisions are closed by contraction of the current-activated SMA wires that are integrated into the chamber. These pull the fracture surfaces into contact, enabling the healing. (ii) The heat generated during the activation of the SMA wires is synergistically exploited for accelerating the healing. (iii) Lastly, during pneumatic actuation, the wires constrain radial expansion and one-side longitudinal extension of the soft chamber, effectuating the desired actuator bending motion. This novel approach of healing is studied via mechanical and ultrasound tests on the specimen level, as well as via bending characterization of the pneumatic robot in multiple damage healing cycles. This technology allows soft robots to become more independent in terms of their self-healing capabilities from human intervention. 

Soft robots with modular designs offer repair and reconfiguration capabilities, which are essential for applications that require resilience, flexibility, and adaptability. This study presents a fully modular soft robot that utilizes origami-based actuator modules composed of reversible polymers and flexible, autonomous joints. This work discusses the advantages of reversible polymers in modular soft robots. The reversible bonding capability of these polymers can be utilized to create high-strength interfaces between modules that rely on strong covalent bonds. These interfaces can be bonded and unbonded at will by controlling the temperature. This principle of reversible bonding is scalable and allows for reconfiguration and flexible bonding. Furthermore, reversible crosslinking enables the fabrication of solid-state origami-based structures, involving sequential folding and unfolding. This process transforms 2D patterns into functional, airtight 3D structures, which can be considered as soft actuators. Additionally, these reversible bonds introduce a self-healing capability into modular soft robots, allowing them to recover from macroscopic damage. These innovations were demonstrated on modular actuator modules based on vacuum origami. The modules sustained damage and successfully performed a self-healing and reconfiguration process. 

Insects maintain remarkable agility after incurring severe injuries or wounds. Although robots driven by rigid actuators have demonstrated agile locomotion and manipulation, most of them lack animal-like robustness against unexpected damage. Dielectric elastomer actuators (DEAs) are a class of muscle-like soft transducers that have enabled nimble aerial, terrestrial, and aquatic robotic locomotion comparable to that of rigid actuators. However, unlike muscles, DEAs suffer local dielectric breakdowns that often cause global device failure. These local defects severely limit DEA performance, lifetime, and size scalability. We developed DEAs that can endure more than 100 punctures while maintaining high bandwidth (>400 hertz) and power density (>700 watt per kilogram)—sufficient for supporting energetically expensive locomotion such as flight. We fabricated electroluminescent DEAs for visualizing electrode connectivity under actuator damage. When the DEA suffered severe dielectric breakdowns that caused device failure, we demonstrated a laser-assisted repair method for isolating the critical defects and recovering performance. These results culminate in an aerial robot that can endure critical actuator and wing damage while maintaining similar accuracy in hovering flight. Our work highlights that soft robotic systems can embody animal-like agility and resilience—a critical biomimetic capability for future robots to interact with challenging environments. 

Lately, soft fluidic actuation has gained widespread interest in all fields where compliance and adaptability are the main keywords. Despite their well-known advantages, soft fluidic actuators frequently present problems related to the elastomeric chambers' durability, affecting the overall system robustness and safety. Indeed, if a robot relies on the parallel pressurisation of multiple actuators, the burst of a single chamber leads to the failure of the entire fluidic circuit, with consequent potentially hazardous leaks. Here, we present the development of a Soft Mini-Fuse (SMIF) valve able to secure and maintain the system functionality even in case of burst failure of single components without affecting their overall bulkiness. By modelling the valve through both analytical and finite element tools, we defined the correlation between main geometrical features, material properties and a selected range of blocking pressures (0.1–1.0 bar). Finally, after validating the modelling tools, we characterised the device behaviour in a range of commonly employed actuation flows (0–15 l/min). The compact dimensions, the ease of integration and the demonstrated performances underline that the SMIF valve represents a novel valuable ally that guarantees stable actuation, limits human intervention and paves the way towards more resilient and autonomous soft fluidic robotic systems. 

Insects maintain remarkable agility after incurring severe injuries or wounds. Although robots driven by rigid actuators have demonstrated agile locomotion and manipulation, most of them lack animal-like robustness against unexpected damage. Dielectric elastomer actuators (DEAs) are a class of muscle-like soft transducers that have enabled nimble aerial, terrestrial, and aquatic robotic locomotion comparable to that of rigid actuators. However, unlike muscles, DEAs suffer local dielectric breakdowns that often cause global device failure. These local defects severely limit DEA performance, lifetime, and size scalability. We developed DEAs that can endure more than 100 punctures while maintaining high bandwidth (>400 hertz) and power density (>700 watt per kilogram)—sufficient for supporting energetically expensive locomotion such as flight. We fabricated electroluminescent DEAs for visualizing electrode connectivity under actuator damage. When the DEA suffered severe dielectric breakdowns that caused device failure, we demonstrated a laser-assisted repair method for isolating the critical defects and recovering performance. These results culminate in an aerial robot that can endure critical actuator and wing damage while maintaining similar accuracy in hovering flight. Our work highlights that soft robotic systems can embody animal-like agility and resilience—a critical biomimetic capability for future robots to interact with challenging environments.