Delicate Objects Research Articles

Gecko-inspired adhesion enhanced by electroadhesive forces

Abstract Soft robotic manipulators have been increasingly adopted over the last decade due to their passive conformation to the shapes of objects, which can reduce control complexity. The performance of these grippers can be improved using flexible adhesive skins that increase tactile gripping forces, which is particularly important when grasping delicate objects and flexible substrates that are otherwise difficult to manipulate. In this work, we investigate how passive gecko-inspired fibrillar adhesion can be augmented by actively controlled electroadhesion (EA). The passive gecko-inspired outer skin (GS) enables adhesion with no power consumption while EA is controlled with an applied voltage. A numerical finite-element model is used to investigate how EA is affected by a commercially available gecko-inspired skin. The results show that the dielectric properties of the gecko-inspired skin reduce the magnitude of field intensity on the adhesive contact surface by only 2.1% at 3 kV. Compared with GS alone, EA with gecko-inspired skin (EAGS) increases the shear force by 66.8% and the normal force by 53.7% with an applied voltage of 4 kV. It is shown that the gecko skin’s adhesion force is enhanced by increased engagement of the fibrillar microstructure to object surfaces due to EA. This is experimentally demonstrated using frustrated total internal reflection imaging. This work shows that electroadhesive-enhanced gecko-inspired skin generates a greater adhesive force than the sum of forces from the separate gecko-inspired skin and EA. In this way, electrically controllable and passive adhesion mechanisms can be combined to improve the handling of flexible and delicate objects with smooth or rough surfaces.

Multi-layered morphing soft structure with high-performance embedded electrothermal artificial muscles along with touch and temperature sensors

Abstract In this paper, we present a novel multilayered morphing structure, having similar topology resembling the structures found in nature to grasp delicate objects effectively as well as sense contact force and temperature. The structure consists of two actuation layers, two U-shaped cooling channel layers, piezoelectric based touch sensors and temperature sensors. Employing shape memory alloy (SMA) spring actuators for bending and twisted and coiled polymer fishing line with nichrome (TCPFL NMC) artificial muscles for antagonistic return, the soft silicone-based composite skin exhibits unique capabilities of large bidirectional movement, avoid rigid passive springs for return motion, soft grasping, safe interaction with humans, and ease fabrication. The SMA (0.38 mm wire diameter) serves as relatively fast actuating muscle and the TCPFL NMC (0.8 mm fiber diameter) as a slow actuating (considering mainly heating cycle), which was programmed/designed to mimic the fast and slow twitching muscles found in nature. Bending and return operations of skin samples of length 100 mm and thickness of 9 mm, with three different widths 20 mm, 25 mm, 30 mm, were experimentally studied. The 25 mm wide multilayered soft skin demonstrated cyclic actuation with a maximum bending angle of ∼70°, which was attributed due to the active cooling. The fluidic channels for active cooling were fabricated using 3D printed PVA tubes, casting within the silicone in a mold and subsequently dissolving in a circulating water. The study also included the integration and voltage response of mini-piezodisk sensor PIC255 having a diameter of 2 mm and thickness of 0.15 mm, which was embedded at different depths within the silicone (on the surface, 1 mm depth and 2 mm depth). The multilayered soft skin was also able to detect the temperature of the object during grasping, suggesting its potential application as a soft gripper in robotic systems.

H‐PME: Development of a Robot Skin Using Halbach Array Permanent Magnet Elastomer

This article presents a novel 3‐axis Halbach permanent magnet elastomer (H‐PME) sensor for the robotic application, which effectively reduces crosstalk along when two sensors are used simultaneously in close proximity, for example, during grasping of thin and delicate objects, needle threading, etc. This sensor integrates a Halbach‐array magnetic elastomer, a 3×3 Hall sensor matrix, and a silicone layer. The magnetic elastomer is produced by combining NdFeB powders with a diameter of 5 μm into silicone, following a weight ratio of 50%, and then magnetized using 2D Halbach‐array magnets. Simulation results reveal the capability to adjust magnetic field strength and distribution by altering the magnet's orientation. The sensor's efficacy in 3‐axis sensing is validated through calibration with a linear model, achieving a good root‐mean‐square error below 0.7 N in force measurement. The H‐PME sensor, with a thickness of merely 4.5 mm, can detect forces up to 50 N. It's simple 3‐layer design allows the thickness to be reduced to as low as 2 mm, while also offering ease of replacement. Crucially, crosstalk evaluation experiments show that the proposed H‐PME sensor can dramatically mitigate crosstalk interference.

Static Model of the Underwater Soft Bending Actuator Based on the Elliptic Integral Function

Underwater soft manipulators are increasingly used for grasping underwater organisms and cultural relics due to their compliance and ability to protect delicate objects. Unlike rigid manipulators, these soft manipulators feature underwater soft bending actuators that deform under external forces, making their shape and output force challenging to predict. Consequently, classical beam theory is no longer applicable. To address these issues, this article models the underwater soft bending actuator as a cantilever beam and establishes its shape and output force using elliptic integral functions. Additionally, this article proposes a method for determining the unknown parameters of the driver shape and output force model using optimization techniques and introduces a solution process based on the particle swarm optimization framework. Given the role of tensile and bending stiffness in the actuator’s performance, this paper employs a parameter identification method based on length and bending angle information. Tests demonstrate that the proposed method effectively estimates the deformation and output force of the underwater soft bending actuators, confirming its accuracy.

Modular reconfigurable rotary style soft pneumatic actuators

Modular soft robots have the advantage in their ability to be reconfigured and change their morphology on-demand according to a specified task. The actuator design and particularly the inter-unit connectivity strength commonly govern the usability and functionality of these modular robots and their applications. In this paper, we present development of reconfigurable modular rotary soft actuators that allow the construction of highly versatile soft robotic actuators and systems. These pneumatically driven modular actuators are composed of an inner balloon and a flexible arched reinforcement structure to produce a rotary motion. They serve as building blocks which may be combined in various configurations to construct linear assemblies capable of extensile or bending motions. The connection scheme allows for the larger actuators to grow or shrink with the addition or removal of modules. Using finite element simulations and physical characterizations, we systematically explore the mechanical response of individual modular actuators and the role of various connection schemes on their motions upon pressurization. A key conceptual contribution of this work lies in the idea that for a modular soft robotic system, offsetting and tuning actuator alignment relative to an axis of symmetry can lead to substantial changes in mechanical performance. Utilizing these modules we demonstrate the reconfigurability of this modular system by both reconfiguring a large actuator into a pair of smaller actuators that can grasp delicate objects, and reconfiguring actuators to develop a linear crawling robot.

Enhancing compliant gripper performance: Exploiting electro-adhesion to increase lifting force over grasping force

On the landscape of solutions to deal with delicate objects, the development and use of soft grippers is a topic of increasing interest, with a large number of prototypes proposed by the research community employing non-linear soft materials and based on diverse actuation means. However, increasing compliance usually leads to the reduction of lifting capacity. As a recent promising approach, shear forces exerted by a soft gripper can be enhanced by exploiting the electro-adhesion (EA) effect. Following this research trend, this paper proposes a new gripper that combines a compliant finger structure, with geometry taken from the FESTO FinRay but made of a softer material (a urethane rubber), and custom EA pads that are placed on the fingers at the interface with the grasped object. Following hyper-elastic model identification of the considered material and preliminary functional verification of gripper design via finite element simulations, the gripper is then manufactured and tested by means of a specific setup, replicating the grasping and lifting of cylindrical objects with different diameters. The results clearly show that the new gripper makes it possible to generate holding forces similar to those of the FESTO FinRay, but with significantly lower pressures on the grasped object (77 % less). Besides enabling the handling of more fragile items, the drastic increase in gripper compliance also results in lower mechanical actuation force (namely, 71 % less of gripping energy) required to generate the same holding force, with a consequent reduction of operation costs and sustainability of its application.

Soft Robotic System with Continuum Manipulator and Compliant Gripper: Design, Fabrication, and Implementation

This paper presents the design, construction, and implementation of a soft robotic system comprising a continuum manipulator arm equipped with a compliant gripper. Three main objectives were pursued: (1) developing a soft silicone gripper as an alternative to expensive and rigid steel grippers, enabling safe and precise handling of delicate or irregular objects such as fruits, glassware, and irregular shapes; (2) fabricating a continuum manipulator arm with robotic joints inspired by vertebrae, allowing for smooth, non-linear motion and more excellent maneuverability compared to traditional rigid arms, enabling access to hard-to-reach areas; and (3) integrating the compliant gripper with the continuum manipulator and implementing a control system for the soft gripper and remote bending arm using a microcontroller. The soft gripper, manipulator arm vertebrae, and other components were fabricated using 3D printing with PLA material for the molds. The gripper construct used hyperelastic silicone (Ecoflex 00.30). The continuum manipulator achieved a higher degree of freedom and mobility, while simulations and experiments validated the design’s effectiveness. The comparison shows that the close agreements differ by only 2.5%. In practical experiments involving lifting objects, the gripper was able to carry items with a greater mass. The proposed soft, integrated robotic system outperformed traditional rigid approaches, offering safe and flexible handling capabilities in unstructured environments. The nature-inspired design enabled a compliant grip and enhanced maneuverability, making it suitable for various applications requiring dexterous manipulation of delicate or irregularly shaped objects.

Mitte ainult mängu asi

Doll Lottchen is an example of a museum object that has changed its nature and functions throughout its lifespan, so it can be described as a toy and as a comfort object, but also as a symbolic item of personal childhood and national identity, and a delicate museum object with restrictions in use. Doll Lottchen belonged to Anne, who was given it as a gift in 1947, during a film shooting in Saint Petersburg (then Leningrad) by the host of a local family, when she was four years old. She found the little smiling doll lovely and called her Lottchen. Anne believed that the doll was produced in Germany and was probably taken as a trophy by some Soviet soldier at the end of the Second World War, but the moulded mark shows that the doll was made in Okhta factory in Russia. Its origin is still unclear as Rheinische Gummi- und Celluloidfabrik in Germany indeed launched a similar doll called Mädi between 1930 and 1957. The Okhta factory used German moulds in the 1930s and 1940s. Sometimes detecting the history of the previous usage of a museum object needs effort and time; for Lottchen the material was collected within eight months of communication with the donator. As Lottchen was an affective object or sensitive object (Frykman and Frykman) there are various memories about it. Anne describes three dramatic episodes from her childhood, during which the doll was either temporarily lost or broken by a dog. At the age of ten the life story of Anne and the story of her favourite doll intersected. Accidentally Anne learned from a tipsy neighbour that she was actually a “German girl”. During two years, when she kept this shocking information a secret and made a new costume for the doll, her doll Lottchen acquired a new meaning. When Anne became 12, it was revealed that she had been rescued by her Estonian stepmother from Königsberg in 1946. By then the city had been destroyed by the allies and occupied by the Soviet forces; thousands of civilians had died of diseases and starvation. Anne was three and a half, her biological family had lost the father and two other children, and little Roswitha Anne Browarzyck (her actual name) was very fragile, with her feet swollen from hunger. Miraculously escaped to Estonia with her future stepmother, she had to hide her East-Prussian origin and was not allowed to speak German. So she quickly forgot her real identity. When finally donating the doll to the museum, Anne sent her off with the following words of farewell: “May you, dear Lottchen, have many good friends and excitement on every day at the toy museum! Maybe I’ll come to see you sometime! Hugs, your Rose (that’s how I was called at home).” As toy museums tend to be places of childhood nostalgy and the Tartu Toy Museum is no exception, there are some dilemmas about dealing with this kind of objects. As they are made of hazardous and fragile celluloid, the best way to preserve them is to keep them in controlled conditions in the repository. Today doll Lottchen is kept this way. However, as a modern museum would like to exhibit its items and share its collections with visitors, there are ethical questions of how to organise it. It is argued whether the happy-faced doll could be displayed in a showcase together with other celluloid dolls without any explanations, to follow the toy museum’s current policy to keep any war themes or sensitive topics of children’s life as silent as possible. Or should toy museums take a more active part in highlighting uneasy topics and white spots in history? Today the world is dangerous and the ongoing war in Ukraine raises questions about war, forcing parents to find ways to answer them. By means of historical stories about toys and children to whom they belonged, museums could contribute to this task. It seems that the best way could be to conduct visitor´s research among children and adults both through surveys and observations. In this way it could be possible to find out what is preferred and whether and how to deal with difficult topics through temporary exhibitions, events or museum education.

Multi-Degree-of-Freedom Force Sensor Incorporated into Soft Robotic Gripper for Improved Grasping Stability.

In recent years, soft robotic grippers have emerged as a promising solution for versatile and safe manipulation of objects in various fields. However, precise force control is critical, especially when handling delicate or fragile objects, to avoid excessive grip force application or to prevent object slippage. Herein, we propose a novel three-degree-of-freedom force sensor incorporated within a soft robotic gripper to realize stable grasping with force feedback. The proposed optical sensor employs lightweight and compact optical fibers, thereby allowing for cost-effective fabrication, and a robust sensing system that is immune to electromagnetic fields. By innervating the soft gripper with optical fibers, a durable system is achieved with the fibers functioning as a strengthening layer, thereby eliminating the need for embedding an external stiffening structure for efficient bending actuation. The innovative contact-based light loss sensing mechanism allows for a robust and stable sensing mechanism with low drift (<0.1% over 9000 cycles) that can be applied to soft pneumatic bending grippers. We used the developed sensor-incorporated soft gripper to grasp various objects, including magnetic materials, and achieved slip detection along with grip force feedback without any signal interference. Overall, this study proposes a robust measuring multi-degree-of-freedom force sensor that can be incorporated into grippers for improved grasping stability.

Quantitative softness and texture bimodal haptic sensors for robotic clinical feature identification and intelligent picking.

Replicating human somatosensory networks in robots is crucial for dexterous manipulation, ensuring the appropriate grasping force for objects of varying softness and textures. Despite advances in artificial haptic sensing for object recognition, accurately quantifying haptic perceptions to discern softness and texture remains challenging. Here, we report a methodology that uses a bimodal haptic sensor to capture multidimensional static and dynamic stimuli, allowing for the simultaneous quantification of softness and texture features. This method demonstrates synergistic measurements of elastic and frictional coefficients, thereby providing a universal strategy for acquiring the adaptive gripping force necessary for scarless, antislippage interaction with delicate objects. Equipped with this sensor, a robotic manipulator identifies porcine mucosal features with 98.44% accuracy and stably grasps visually indistinguishable mature white strawberries, enabling reliable tissue palpation and intelligent picking. The design concept and comprehensive guidelines presented would provide insights into haptic sensor development, promising benefits for robotics.

Experimental investigation on enhancement in pure axial deformation of soft pneumatic actuator (SPA) with cap ring reinforcement

Bio-inspired soft-robots are nowadays found their place in many applications due to its flexibility, compliance and adaptivity to unstructured environment. The main intricate part of such bio-inspired soft robots are soft pneumatic actuators (SPA) which replicate or mimic the limbs and muscles. The soft actuators are pneumatically actuated and provide bending motion in most cases. However, many engineering and medical applications need axially expanding soft pneumatic actuators to deal with delicate objects. Various studies have put forward designs for SPA with axial deformation, but the majority of them have limited axial deformation, constraining motion and less overall efficacy which limit the scope of utilization. The common practice to enhance the axial deformation of SPA is by incorporating directionally customized reinforcement using fibres or by other means like yarns, fabrics, etc These types of reinforcements are generally embedded to SPA during fabrication and may not have capability for any correction or modification later on hence lack the customization. This paper presents a novel method of radial reinforcement for the enhancement of axial deformation of SPAs with provision of customization. The present study aims to enhance and/or customize the axial deformation of SPA by incorporating external and detachable reinforcement in the form of annulus shaped cap ring. The investigation encompasses the design and attachment of four distinct cap ring geometries to SPA at different locations. Experimental results affirm that cap ring reinforcement bolster the radial stiffness, curbing lateral deformation while permitting axial deformation of soft pneumatic actuators. Out of 64 distinct configurations, the one with full reinforcement, featuring four cap rings of maximum size, yields a remarkable 169% increase in pure axial deformation compared to unreinforced cases. It is also observed that by varying the number and placement locations of cap rings the pure axial deformation can be customized. This novel insight not only propels soft pneumatic actuation technology but also heralds prospects for highly agile and versatile robotic systems which can be used in medical, prosthetics, pharmaceutical and other industries.

Tactile Sensing and Grasping Through Thin‐Shell Buckling

Soft and lightweight grippers have greatly enhanced the performance of robotic manipulators in handling complex objects with varying shape, texture, and stiffness. However, the combination of universal grasping with passive sensing capabilities still presents challenges. To overcome this limitation, a fluidic soft gripper is introduced based on the buckling of soft, thin hemispherical shells. Leveraging a single fluidic pressure input, the soft gripper can grasp slippery and delicate objects while passively providing information on this physical interaction. Guided by analytical, numerical, and experimental tools, the novel grasping principle of this mechanics‐based soft gripper is explored. First, the buckling behavior of a free hemisphere is characterized as a function of its geometric parameters. Inspired by the free hemisphere's two‐lobe mode shape ideal for grasping purposes, it is demonstrated that the gripper can perform dexterous manipulation and gentle gripping of fragile objects in confined spaces and underwater environments. Last, the soft gripper's embedded capability of detecting contact, grasping, and release conditions during the interaction with an unknown object is proved. This simple buckling‐based soft gripper opens new avenues for the design of adaptive gripper morphologies with tactile sensing capabilities for applications ranging from medical and agricultural robotics to space and underwater exploration.

Bioinspired flexible gripper for vacuum non-cooperative target capture

With the development of space exploration activities, the proliferation of non-cooperative targets in space, such as defunct satellites and space debris, has made the development of efficient and reliable non-cooperative target capture technologies in space a priority for space exploration. In this paper, a flexible gripper inspired by the dermo-muscular sac found in flatworms is presented to address the challenges of non-cooperative target capture in the vacuum environment of space. The gripper design leverages magnetorheological fluid and a magnetic field to enable adjustable stiffness, facilitating the effective grasping of delicate target objects while ensuring a stable connection post-capture. Extensive tests demonstrate the strong potential of the gripper for space applications, showcasing its ability to adjust pre-grip contact force and increase gripping force by adjusting indentation depth. The simplicity of the design contributes to ease of manufacturing, making it a promising tool for future space missions.

Versatile 3D-printed fin-ray effect soft robotic fingers: lightweight optimization and performance analysis

Fin ray soft robotic fingers are inspired by the structure and movement of fish fins, enabling flexible and adaptive grasping capabilities. Addressing the challenges of resource efficiency in terms of reduced energy consumption and material expense, this work focuses on further optimizing inherently low-energy fin-ray fingers towards lightweight design. Soft grippers are used frequently in dynamically changing environments and have become inevitable in handling tasks for delicate objects. However, these grippers generally show limited performance and payload-carrying capacity in high-force application scenarios. To address these limitations, topology optimization technique is used here to obtain both gripping capabilities and high factor of safety (FOS) of fingers. The performance of various structures of fin-ray and optimized fingers are analyzed: rectangular, trapezoidal, straight struts, and inclined struts for angles + 45°, − 45°. The topologically optimized structure has 15.2% less mass compared to considered fin-ray finger’s average mass. The deflection coefficient (Cd) is calculated to select the best structure of the fingers based on grasping scenario, and its value should be minimum. The straight strut finger with thickness of t = 2 mm shows best wrapping capabilities compared to all fingers with Cd = 0.1574. The topologically optimized finger’ Cd = 0.1896 at volume fraction of 0.1. Even though the Cd is slightly higher, its FOS is 1.71 times higher. An experimental setup is developed to validate the simulation results with the help of a UR3e robotic arm and an AXIA80 force sensor. The grasping demonstration of soft robotic gripper is performed on various objects: coffee cup and wooden block.

Seahorse-Tail-Inspired Soft Pneumatic Actuator: Development and Experimental Characterization.

The study of bio-inspired structures and their reproduction has always fascinated humans. The advent of soft robotics, thanks to soft materials, has enabled considerable progress in this field. Over the years, polyps, worms, cockroaches, jellyfish, and multiple anthropomorphic structures such as hands or limbs have been reproduced. These structures have often been used for gripping and handling delicate objects or those with complex unknown a priori shapes. Several studies have also been conducted on grippers inspired by the seahorse tail. In this paper, a novel biomimetic soft pneumatic actuator inspired by the tail of the seahorse Hippocampus reidi is presented. The actuator has been developed to make a leg to sustain a multi-legged robot. The prototyping of the actuator was possible by combining a 3D-printed reinforcement in thermoplastic polyurethane, mimicking the skeletal apparatus, within a silicone rubber structure, replicating the functions of the external epithelial tissue. The latter has an internal channel for pneumatic actuation that acts as the inner muscle. The study on the anatomy and kinematic behaviour of the seahorse tail suggested the mechanical design of the actuator. Through a test campaign, the actuator prototype was characterized by isotonic tests with an external null load, isometric tests, and activation/deactivation times. Specifically, the full actuator distension of 154.5 mm occurs at 1.8 bar, exerting a maximum force of 11.9 N, with an activation and deactivation time of 74.9 and 94.5 ms, respectively.

Chryselephantine Couches, Feasting, and Imperial Violence in Hellenistic Macedonia

Macedonian chryselephantine couches - exquisitely carved and gleaming with gold, glass, and ivory - offer a particularly illuminating case study of the material ramifications of Alexander the Great’s conquests for Hellenistic art. Well-documented in archaeological remains and written texts, the couches also offer a concrete lens through which to analyze the transfer of cultural knowledge about feasting: an ephemeral activity as significant for Hellenistic kings as for their Persian predecessors. This article examines the couches’ archaeological contexts, the aristocratic tombs in which they were found and the elaborate palaces and elite houses in which they were likely first used. It then analyzes the couches themselves as delicate luxury objects that nonetheless, in their iconography, style, and even their material, highlighted the violence of Macedonian imperialism. And finally, it considers the ephemeral practices through which the couches were activated for their patrons, that is, the feasts and funerals at which the Macedonian aristocracy both emulated and reacted against Persian precedents. This re-evaluation of Macedonian chryselephantine couches illuminates global interconnections during the formative period of Hellenistic art.

Soft Robot Design, Manufacturing, and Operation Challenges: A Review

Advancements in smart manufacturing have embraced the adoption of soft robots for improved productivity, flexibility, and automation as well as safety in smart factories. Hence, soft robotics is seeing a significant surge in popularity by garnering considerable attention from researchers and practitioners. Bionic soft robots, which are composed of compliant materials like silicones, offer compelling solutions to manipulating delicate objects, operating in unstructured environments, and facilitating safe human–robot interactions. However, despite their numerous advantages, there are some fundamental challenges to overcome, which particularly concern motion precision and stiffness compliance in performing physical tasks that involve external forces. In this regard, enhancing the operation performance of soft robots necessitates intricate, complex structural designs, compliant multifunctional materials, and proper manufacturing methods. The objective of this literature review is to chronicle a comprehensive overview of soft robot design, manufacturing, and operation challenges in conjunction with recent advancements and future research directions for addressing these technical challenges.

Liftoff of a soft-actuated micro-aerial-robot powered by triboelectric nanogenerators

Aerial insects can nimbly navigate in cluttered natural environments while they interact with delicate objects such as flowers and leaves. To achieve insect-like agility and robustness, power dense dielectric elastomer actuators (DEAs) have been developed for driving sub-gram micro-aerial-vehicles (MAVs). However, despite exhibiting muscle-like bandwidth and resilience, DEAs require a high driving voltage in the range of 1 – 2 kilovolts. This requirement poses substantial challenges for developing compact boost electronics and energy sources, which prohibit power autonomous operations of soft-actuated sub-gram MAVs. Here, we develop a compact and high power triboelectric nanogenerator (TENG) that can effectively charge a high-voltage DEA and enable the liftoff of a soft-actuated MAV. We propose an In-plane Charge Pump (ICP) design that can deliver over 1500 V and 110 mW without requiring a secondary charge pump or magnetic circuit components such as inductors or transformers. Compared to conventional free-standing mode TENGs, our ICP design shows a 280 % and 920 % increase in voltage and energy generation, respectively. When this TENG powers a DEA-driven MAV, the 160 mg robot achieves liftoff with a lift-to-weight ratio of 1.75. This result highlights the potential of powering high-voltage microrobots with energy-harvesting devices.

The Claw: An Avian-Inspired, Large Scale, Hybrid Rigid-Continuum Gripper

Most robotic hands have been created at roughly the scale of the human hand, with rigid components forming the core structural elements of the fingers. This focus on the human hand has concentrated attention on operations within the human hand scale, and on the handling of objects suitable for grasping with current robot hands. In this paper, we describe the design, development, and testing of a four-fingered gripper which features a novel combination of actively actuated rigid and compliant elements. The scale of the gripper is unusually large compared to most existing robot hands. The overall goal for the hand is to explore compliant grasping of potentially fragile objects of a size not typically considered. The arrangement of the digits is inspired by the feet of birds, specifically raptors. We detail the motivation for this physical hand structure, its design and operation, and describe testing conducted to assess its capabilities. The results demonstrate the effectiveness of the hand in grasping delicate objects of relatively large size and highlight some limitations of the underlying rigid/compliant hybrid design.

Digital Light Processing of Soft Robotic Gripper with High Toughness and Self‐Healing Capability Achieved by Deep Eutectic Solvents

AbstractInspired by nature's flexible and adaptable organisms, soft robotics are motorless robots made from highly compliant materials to work in confined environments and manipulate delicate objects. However, soft robots often suffer from early failure because of unexpected damage. At the same time, it is challenging to manufacture the geometrically complex structures of soft robots. This study introduces resins based on deep eutectic solvents (DES) to fabricate a pneumatically driven soft gripper using digital light processing (DLP). The resins consist of choline chloride (ChCl) as a hydrogen bond acceptor, glycerol (Gly), and acrylamide (AAm) as hydrogen bond donors. By utilizing the intense hydrogen bonding within DES, the resin can be rapidly cured by photopolymerization to form tough ionogels without chemical crosslinkers. The DES ionogels exhibit remarkable toughness and self‐healing performance compared to common hydrogels. Furthermore, the ionogels show not only efficient energy‐dissipating behavior but also achieve rapid self‐recovery. Finally, the DLP‐printed soft gripper from the DES‐based resin performs successful actuation and healing of macroscopic damages. This work presents a simple strategy to 3D print a soft robotic gripper with high toughness and self‐healing capability.