Journal of Bionic Engineering最新文献

This paper introduces a self-sensing anthropomorphic robot hand driven by Twisted String Actuators (TSAs). The use of TSAs provides several advantages such as muscle-like structures, high transmission ratios, large output forces, high efficiency, compactness, inherent compliance, and the ability to transmit power over distances. However, conventional sensors used in TSA-actuated robotic hands increase stiffness, mass, volume, and complexity, making feedback control challenging. To address this issue, a novel self-sensing approach is proposed using strain-sensing string based on Conductive Polymer Composite (CPC). By measuring the resistance changes in the strain-sensing string, the bending angle of the robot hand's fingers can be estimated, enabling closed-loop control without external sensors. The developed self-sensing anthropomorphic robot hand comprises a 3D-printed structure with five fingers, a palm, five self-sensing TSAs, and a 3D-printed forearm. Experimental studies validate the self-sensing properties of the TSA and the anthropomorphic robot hand. Additionally, a real-time Virtual Reality (VR) monitoring system is implemented for visualizing and monitoring the robot hand's movements using its self-sensing capabilities. This research contributes valuable insights and advancements to the field of intelligent prosthetics and robotic end grippers.

The earthworm has been attracted much attention in the research and development of biomimetic robots due to their unique locomotion mechanism, compact structure, and small motion space. This paper presents a new design and prototype of a worm-inspired metameric robot with a movement pattern similar to that of earthworms. The robot consists of multiple telescopic modules connected in series through joint modules. The telescopic module mimics the contraction and elongation motion modes of the earthworm segments. A kinematic and dynamic analysis is conducted on the telescopic module, and an input torque calculation method is provided to ensure sufficient friction between the robot and the pipe wall. The gait modes of the prototype robot for straight and turning locomotion are introduced, and these modes are extended to robots constructed by different numbers of telescopic modules. In addition, a method is proposed to increase the friction between the robot and the pipe wall in the aforementioned gait modes without changing the robot structure, thereby improving the robot’s motion ability in pipelines. The theoretical model of gait modes has also been validated through gait experiments. The findings of this paper would provide a useful basis for the design, modeling, and control of future worm inspired robots.

Surface-tension-confined microfluidic devices are platforms for manipulating 2D droplets based on patterned surfaces with special wettability. They have great potential for various applications, but are still in the early stages of development and face some challenges that need to be addressed. This study, inspired by the Wenzel and slippery transition of rose petal, develops a Patterned Oil-triggered Wenzel-slippery Surface (POWS) to examine the microfluidic devices. A laser-chemical composite method is established to fabricate POWSs, which take rose-petal-like microstructures as wettability pattern and a superamphiphobic surface as the background. The prepared POWSs switched between high adhesion superhydrophobic state and the slippery liquid-infused surface state through adding or removing the lubricant oil. In the high adhesion superhydrophobic state, the droplets can be sticked on the surface. In the slippery liquid-infused state, the droplet can slide along the wettability pattern as the designed route. A POWS-based droplet reactor is further constructed, on which, the droplets can be remotely controlled to move, mix and react, as required. Such a POWS, which manipulates droplets with surface tension controlled by the switchable wettability patterns, would be a promising candidate to construct multiple surface-tension-confined microfluidic devices. In addition, the fabrication technique and design principle proposed here may aid the development of various field related to the bio-inspired surfaces, such as water collection, desalination and high throughput analysis, etc.

We previously developed a powered hip prosthetic mechanism with kinematic functions of hip flexion–extension and abduction–adduction, and its theoretical and simulation-based kinematics were verified. Because internal–external hip rotation has a positive effect on the movements of human lower limbs according to medical research, we developed a novel hip prosthetic mechanism based on a previous hip prosthesis that possesses motion characteristics similar to those of a human bionic hip, and the motion characteristics of multiple Degrees-of-Freedom (DoFs) were analyzed after kinematic modeling. Then, a walking model of the human‒machine model was established, and the walking stability of an amputee, which reflects the rehabilitation effect, was explored while the hip prosthetic mechanism considered the internal–external rotation of the hip. Finally, a prototype and its verification platform were built, and kinematic validation of the hip prosthetic mechanism was carried out. The results showed that the designed Parallel Mechanism (PM) possesses human-like motion characteristics similar to those of a human bionic hip and can be used as a hip prosthesis. Moreover, the existing motion characteristic of internal–external hip rotation can enhance the walking stability of an amputee via this hip prosthetic mechanism.

The disparity between the postoperative outcomes of rhinoplasty and the expected results frequently necessitates secondary or multiple surgeries as a compensatory measure, greatly diminishing patient satisfaction. However, there is renewed optimism for addressing these challenges through the innovative realm of Four-Dimensional (4D) printing. This groundbreaking technology enables three-dimensional objects with shape-memory properties to undergo predictable transformations under specific external stimuli. Consequently, implants crafted using 4D printing offer significant potential for dynamic adjustments. Inspired by worms in our research, we harnessed 4D printing to fabricate a Shape-Memory Polyurethane (SMPU) for use as a nasal augmentation prosthesis. The choice of SMPU was guided by its Glass Transition Temperature (T_g), which falls within the acceptable temperature range for the human body. This attribute allowed for temperature-responsive intraoperative self-deformation and postoperative remodeling. Our chosen animal model for experimentation was rabbits. Taking into account the anatomical structure of the rabbit nose, we designed and produced nasal augmentation prostheses with superior biocompatibility. These prostheses were then surgically implanted in a minimally invasive manner into the rabbit noses. Remarkably, they exhibited successful temperature-controlled in-surgery self-deformation according to the predetermined shape and non-invasive remodeling within a mere 9 days post-surgery. Subsequent histological evaluations confirmed the practical viability of these prostheses in a living organism. Our research findings posit that worm-inspired 4D-printed SMPU nasal prostheses hold significant promise for achieving dynamic aesthetic adjustments.

The creation of 3D nanofibers offering desirable functions for bone regeneration is developed due to the latest improvisations to the electrospinning technique. Synthetic polymers are among the best choices for medical usage due to their lower costs, high tensile properties, and ease of spinnability compared to natural polymers. In this communication, we report a series of interventions to polymers modified with Mg-based fillers for ideal tissue engineering applications. The literature survey indicated that these filler materials (e.g., nano-sized particles) enhanced biocompatibility, antibacterial activity, tensile strength, and anti-corrosive properties. This review discusses electrospinning parameters, properties, and applications of the poly(ε-caprolactone), poly(lactic acid), poly(3-hydroxybutyric acid-co-3-hydroxy valeric acid), polyurethane, and poly(vinyl pyrrolidone) nanofibers when modified with Mg-based fillers. This report encourages researchers to use synthetic polymers with Mg as fillers and validate them for tissue engineering applications.

Soft grippers have great potential applications in daily life, since they can compliantly grasp soft and delicate objects. However, the highly elastic fingers of most soft grippers are prone to separate from each other while grasping objects due to their low stiffness, thus reducing the grasping stability and load-bearing capacity. To tackle this problem, inspired from the venus flytrap plant, this work proposes a mutual-hook mechanism to restrain the separation and improve the grasping performance of soft fingers. The novel soft gripper design consists of three modules, a soft finger-cot, two Soft Hook Actuators(SHAs) and two sliding mechanisms. Here, the soft finger-cot covers on the soft finger, increasing the contact area with the target object, two SHAs are fixed to the left and right sides of the finger-cot, and the sliding mechanisms are designed to make SHAs stretch flexibly. Experiments demonstrate that the proposed design can restrain the separation of soft fingers substantially, and the soft fingers with the finger-cots can grasp objects three times heavier than the soft fingers without the proposed design. The proposed design can provide invaluable insights for soft fingers to restrain the separation while grasping, thus improving the grasping stability and the load-bearing capacity.

Cartilage regeneration and repair are considered clinical challenges since cartilage has limited capability for reconstruction. Although tissue-engineered materials have the ability to repair cartilage, they have weak mechanical characteristics and cannot resist long-term overload. On the other hand, surgery to replace the joint is frequently done to treat significant cartilage deterioration these days. However, the materials that are being used for replacement have high friction coefficients, lack shock absorption functions, and lack cushioning. Further research on natural articular cartilage structure and function may lead to bionic hydrogels, which have suitable physicochemical and biological characteristics (e.g., tribological and mechanical properties and the ability to support loadbearing capability), but need improvements. Based on their tribological and mechanical characteristics, the current review highlights the most recent advancements of bionic hydrogels used for articular cartilage, highlighting both the field's recent progress and its potential for future research. For this reason, firstly, some important property improvement methods of bionic hydrogels are discussed and then, the recent findings of various research on the making of those bionic materials are provided and compared. It seems that by using some modifications such as product design, surface treatments, animal tests, controlling the isoelectric point of hydrogels, and computer simulation, the intended mechanical and tribological characteristics of natural articular cartilage may be attained by the bionic hydrogels.

Excellent fluid sealing performance is crucial to ensuring the safety of important equipment, especially in aerospace field, such as space capsule and fuel chamber. The frequently opening and closing of the sealing devices is particularly important. Driven by this background, clams (Mactra chinensis) which can open and close their double shells with superior sealing performance, are studied in this work. Here, we show that the clam’s sealing ability is the result of its unique multilevel intermeshing microstructures, including hinge teeth and micro-blocks. These microstructures, which resemble gear teeth, engage with each other when the shell closes, forming a tight structure that prevents the infiltration of water from the outside. Furthermore, the presence of micron blocks prevents the penetration of finer liquids. The simulation results of the bionic end seal components show that the multilevel microstructure has a superior sealing effect. This research is expected to be applied to undersea vehicles that require frequent door opening and closing.

In recent years, with the increasing demand for social production, engineering design problems have gradually become more and more complex. Many novel and well-performing meta-heuristic algorithms have been studied and developed to cope with this problem. Among them, the Spherical Evolutionary Algorithm (SE) is one of the classical representative methods that proposed in recent years with admirable optimization performance. However, it tends to stagnate prematurely to local optima in solving some specific problems. Therefore, this paper proposes an SE variant integrating the Cross-search Mutation (CSM) and Gaussian Backbone Strategy (GBS), called CGSE. In this study, the CSM can enhance its social learning ability, which strengthens the utilization rate of SE on effective information; the GBS cooperates with the original rules of SE to further improve the convergence effect of SE. To objectively demonstrate the core advantages of CGSE, this paper designs a series of global optimization experiments based on IEEE CEC2017, and CGSE is used to solve six engineering design problems with constraints. The final experimental results fully showcase that, compared with the existing well-known methods, CGSE has a very significant competitive advantage in global tasks and has certain practical value in real applications. Therefore, the proposed CGSE is a promising and first-rate algorithm with good potential strength in the field of engineering design.