Morphing Suction Cups Capable of Bending and Lengthening

The suckers on the octopus arm play a pivotal role in the execution of tasks in unstructured environments by providing a means to grip objects as well as perceive the environment through (chemo‐)tactile receptors in the suckers. This work presents an octopus‐inspired suction cup with high‐resolution tactile sensing capabilities using a camera that captures the displacement of markers that are integrated in the suction cup. The orientation of the suction cup with respect to an object surface could be predicted with an average error of 1.97° for latitude and 9.41° for longitude. In a closed‐loop control experiment, the orientation of the suction cup with respect to the object surface is estimated by an initial touch and the suction cup is consequently reoriented to approach the object surface in a perpendicular manner. The passive compliance of the suction cup is sufficient to compensate for the prediction error and a seal could be created on all of the objects. In combination with the automated design and manufacturing process, this is a major step toward the deployment of sensory innervated suction cups for motion planning and control of soft continuum robot arms.

In certain precision work scenarios, underwater robots require the ability to adhere to surfaces in order to perform tasks effectively. An efficient and stable suction device plays a pivotal role in the functionality of such underwater robots. The vortex suction cup, distinguished by its uncomplicated design, high suction efficiency, and capability for non-contact adhesion, holds significant promise for integration into underwater robotic systems. This paper presents a novel design for a vortex suction cup and investigates its suction force and torque when encountering surfaces with varying curvature radii using Computational Fluid Dynamics (CFD) simulations and experimental testing. These findings offer valuable insights for the development of robots capable of adapting to underwater structures of different dimensions. Results from both experiments and simulations indicate that reducing the curvature radius of the adhered surface results in a decrease in suction force and an increase in torque exerted on the suction cup. As the adhered surface transitions from flat to a curvature radius of 150 mm, the adhesion force of our proposed vortex suction cup decreases by approximately 10%, while the torque increases by approximately 20% to 30%. Consequently, the adhesion efficiency of the suction cup decreases by about 25% to 30%.

Applying suction grippers in unstructured environments is a challenging task because of depth and tilt errors in vision systems, requiring additional costs in elaborate sensing and control. To reduce additional costs, suction grippers with compliant bodies or mechanisms have been proposed; however, their bulkiness and limited allowable error hinder their use in complex environments with large errors. Here, we propose a compact suction gripper that can pick objects over a wide range of distances and tilt angles without elaborate sensing and control. The spring-inserted gripper body deploys and conforms to distant and tilted objects until the suction cup completely seals with the object and retracts immediately after, while holding the object. This seamless deployment and retraction is enabled by connecting the gripper body and suction cup to the same vacuum source, which couples the vacuum picking and retraction of the gripper body. Experimental results validated that the proposed gripper can pick objects within 79 mm, which is 1.4 times the initial length, and can pick objects with tilt angles up to 60 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> . The feasibility of the gripper was verified by demonstrations, including picking objects of different heights from the same picking height and the bin picking of transparent objects.

Conventional suction cups lack sensing capabilities for contact-aware manipulation in unstructured environments. This paper presents FlexiCup, a multimodal suction cup with wireless electronics that integrate dual-zone vision-tactile sensing. The central zone dynamically switches between vision and tactile modalities via illumination control, while the peripheral zone provides continuous spatial awareness. The modular mechanical design supports both vacuum (sustained-contact adhesion) and Bernoulli (contactless lifting) actuation while maintaining the identical dual-zone sensing architecture, demonstrating sensing-actuation decoupling where sensing and actuation principles are orthogonally separable. We validate hardware versatility through dual control paradigms. Modular perception-driven grasping achieves comparable success rates across vacuum (90.0%) and Bernoulli (86.7%) modes using identical sensing and control pipelines, validating the sensing architecture's effectiveness across fundamentally different pneumatic principles. Diffusion-based end-to-end learning achieves 73.3% and 66.7% success on contact-aware manipulation tasks, with ablation studies confirming 13% improvements from multi-head attention coordinating dual-zone observations. Hardware designs, firmware, and experimental videos are available at the companion website: <uri xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">https://flexicup.junhaogong.top</uri>.

Robotic grasp in complicated un-structured warehouse environments is still a challenging task and attracts lots of attentions from robot vision and machine learning communities. A popular strategy is to directly detect the graspable region for specific end-effector such as suction cup, two-fingered gripper or multi-fingered hand. However, those work usually depends on the accurate object detection and precise pose estimation. Very recently, affordance map which describes the action possibilities that an environment can offer, begins to be used for grasp tasks. But it often fails in cluttered environments and degrades the efficiency of warehouse automation. In this paper, we establish an active exploration framework for robot grasp and design a deep reinforcement learning method. To verify the effectiveness, we develop a new composite hand which combines the suction cup and fingers and the experimental validations on robotic grasp tasks show the advantages of the active exploration method. This novel method significantly improves the grasp efficiency of the warehouse manipulators.

Octopus show great adhesion capabilities thanks to their suckers covering their ventral side of their arms. Starting from biological investigation, we identified preliminary specifications for the design of innovative artificial suction cups, which could be used in the field of soft robotics. The main features of the biological sucker are maintained as leading criteria for the choice of the actuation technology and mechanism. In this preliminary work, we focused on the imitation of the functionality of the specific muscle bundles which generate suction to obtain adhesion. Dielectric Elastomers Actuators (DEA) were identified as a suitable solution. A study on materials and manufacturing techniques was made. Different possible solutions in the use of DEA are also described.

World Wide Web search engines have become the most heavily-used online services, with millions of searches performed each day. Their popularity is due, in part, to their ease of use. The central tasks for the most of the search engines can be summarize as 1) query or user information request- do what I mean and not what I say!, 2) model for the Internet, Web representation-web page collection, documents, text, images, music, etc, and 3) ranking or matching functiondegree of relevance, recall, precision, similarity, etc. Design of any new intelligent search engine should be at least based on two main motivations: 1) The web environment is, for the most part, unstructured and imprecise. To deal with information in the web environment what is needed is a logic that supports modes of reasoning which are approximate rather than exact. While searches may retrieve thousands of hits, finding decision-relevant and query-relevant information in an imprecise environment is a challenging problem, which has to be addressed and 2) Another, and less obvious, is deduction in an unstructured and imprecise environment given the huge stream of complex information.KeywordsFuzzy LogicSearch EngineUser ProfileWorld KnowledgeConceptual GraphThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Collaborative robots are growing exponentially, with applications in the most diverse domains and operating side by side with humans in unstructured and changing environments. Such a scenario requires robot programmers to develop complex applications, integrating Artificial Intelligence (AI), sensing and control, both rapidly and efficiently. Python and model-based design software packages such as Simulink are widely used in engineering, and when it comes to robotics those tools are very important for robot design, simulation and the development of control algorithms before the implementation on the real robot. Python is widely used in AI while Simulink supports several hardware components, facilitating rapid deployment of the developed programs on the target hardware. In this study, a novel Python library (iiwaPy) and SimulinkIIWA are presented to interface KUKA iiwa robots. The iiwaPy is based on the Transmission Control Protocol/Internet Protocol (TCP/IP) and the SimulinkIIWA on the User Datagram Protocol (UDP). Both support robot motion control (point-to-point and real-time) at the joint level and the end-effector (EEF) level, as well as the monitoring of the robot state (position, orientation, torques feedback). Open-source code and example applications are provided showing the flexibility and the ease of use of the proposed interfaces.

Tranexamic acid-loaded catechol-modified hyaluronic acid/carboxymethyl chitosan double cross-linked porous gel micropowders for rapid hemostasis and wound healing

PurposeThree-dimensional bioprinting (3D bioprinting) is used for repairing and regenerating living tissues due to its ease of use, cost-effectiveness and high precision in fabricating. Owing to their high biocompatibility, natural hydrogels are widely used as scaffold materials in bioprinting. However, the mechanical properties and low printability of hydrogels present a challenge. This study aims to introduce a composite hydrogel that exhibits excellent mechanical, biological and printability properties simultaneously.Design/methodology/approachAlginate (Alg), carboxymethyl cellulose (CMC) and nanohydroxyapatite (nHA) as suitable materials for 3D printing were used. Effect of material content and pre-crosslinking on various properties of these materials were investigated. Both quantitative and qualitative experiments were conducted to validate the biomaterial ink’s printability, its rheological characteristics, as well as its biological and mechanical properties.FindingsBased on the analysis of the obtained experimental results from all mentioned tests, a hydrogel with a composition of 4% Alg, 2% CMC and 2% nHA with the pre-crosslinking process was selected as the preferred option. The results demonstrated that the selected material has good cell adhesion, wettability, degradation rate and 93% cell viability. Furthermore, compared to the composition of 4% Alg–2% CMC, the chosen material exhibited a 52% improvement in printability and a 55% improvement in compressive modulus.Originality/valueA significant challenge in the field of 3D bioprinting is the development of scaffolds that possesses optimal mechanical, biological and printability characteristics simultaneously, essential for attaining tissue-like properties. Hence, this paper explores a novel nanocomposite hydrogel that demonstrates promising outcomes across all these aspects simultaneously.

The principle of mechanical passive compliance is widely used in interactive robots to ensure the safety of robot interaction. Rigid dexterous hands are inclined to be damaged by physical collisions in unpredictable situations such as unstructured environments or operational errors. As robots are required to manipulate in unpredictable unstructured environments, it is urgent to develop a robust dexterous hand which can guarantee their own safety in the process of interaction. According to the passive compliance principle of mechanical system, a design of flexible joint finger with variable stiffness is proposed in this paper. The main goal is to achieve the robustness of the multi-fingered hands against physical impacts. The maximum fingertip force of the finger reaches 30N. Hammer knocking test proves that it has good resistance to physical impact.

Isotropically conductive adhesive formulations predominantly include epoxy resin as the polymer matrix. Although epoxy has superior adhesion capability, it has a tendency to absorb moisture and is nonreworkable. The presence of water in ICA interconnects causes contact resistance degradation by means of galvanic corrosion. In this study, an alternative polymer matrix with low moisture absorption and potential for reworkability, is used in isotropically conductive adhesive (ICA) formulation. The contact resistance of this group of ICAs is measured throughout an accelerated aging process (85/spl deg/C/85%RH). The four point probe method is used to measure contact resistance on test coupons. Contact resistance stability of the ICAs is compared among test coupons of various surface finishes (OSP, Sn/Pb, Sn, and Ni/Au). SEM analyses are conducted on cross sections of coupons that fail early in the aging process and they are compared with coupons with stable resistance. Adhesion capability of this alternative polymer is compared with epoxy on various surfaces, e.g. OSP, Sn/Pb, Sn, and Ni/Au, using a die shear tester. Coupling agents are incorporated into the ICA formulations and their effects on adhesion and contact resistance stability are studied. Blends of epoxy and this alternative polymer are also evaluated. Contact resistance measurements of a thermoplastic-thermoset ICA blend are collected throughout the aging process. Adhesion data of the ICA blend is also collected using a die shear tester. Such a blend should produce a formulation with good adhesion and low moisture uptake, which will be verified by the experimental results.

Dealing with grasping tasks in unstructured environments, existing soft grippers often exhibit a lack of static stability, while rigid-soft hybrid grippers display limited compliance due to the fixed connections at the joints. To address the challenge of balancing static stability and flexible adaptability, this study designs and implements a bioinspired hybrid gripper combining soft and rigid elements. The gripper draws inspiration from the collateral ligaments and joint capsule structures of human fingers. It employs a tendon-driven mechanism that ensures high static stability while enabling a large range of flexion movements and some degree of deflection, mimicking the dynamic bending of a human finger. Experimental results demonstrate that the hybrid fingers excel in terms of static stability, working range, and output force. Notably, under conditions of extensor tendon pretension, the fingers exhibit finer motion toward the fingertips. The dual-finger gripper performs exceptionally well in various grasping tasks, stably grasping objects of different shapes and weights, such as the Evolved Grasp Analysis Dataset and common daily items. This study offers a novel and straightforward design approach for the development of bioinspired fingers and high-performance robots, holding broad application prospects.

Wound infection is a serious clinical challenge, often accompanied by persistent inflammatory response and the threat of increased bacterial resistance, there is an urgent requirement to develop a wound dressing with potent antimicrobial as well as immunomodulatory effects. In this study, we developed a multifunctional wound dressing to promote healing of infected wounds by doping puerarin-loaded mesoporous polydopamine nanoparticles into a carboxymethyl chitosan/sodium alginate oxide-based hydrogel. The hydrogel has good injectability, adhesion, and self-healing capabilities, and can be well matched to irregular wounds and against external injuries. The loaded PUE is rapidly released from the hydrogel in response to near-infrared (NIR) laser irradiation, which has a controlled release property. In addition, under NIR laser irradiation, the hydrogel with good photothermal properties exerted good antimicrobial properties through localized high temperature, and exhibited good antioxidant, immune microenvironment modulation, and pro-angiogenic effects through accelerated released PUE. In the E. coli-infected full-thickness skin wounds healing experiments, the hydrogel can effectively kill bacteria, regulate the immune microenvironment, promote collagen deposition and angiogenesis, and significantly accelerate the wound healing, showing promising applications.

The ability of mussels to adhere to underwater surfaces has attracted a lot of attention from the scientific community. As proteins containing L‐DOPA (3,4‐dihydroxyphenyl‐l‐alanine) are involved in their adhesion, a common strategy to synthesize adhesives is the incorporation of this amino acid into other compounds. Herein, we report a study on four compounds of the family of Bocx‐(L‐DOPA)n‐OMe (x = 1–3; n = 1,2), that we prepared through simple synthetic steps. Three of them showed the capability of underwater adhesion: while they are not adhesive in the dry phase, the adhesiveness is triggered when the dried sample is immersed in water or any aqueous solutions. The introduction of protecting groups stabilizes L‐DOPA, preventing the oxidation of the catechol moiety, and enhances the hydrophobicity, helping the removal of water from the surface to bind. These molecules show good adhesiveness, with different properties, so they may be all used as adhesives for different purposes. These outcomes pave the way for new applications for these materials as green and biocompatible adhesives.