Maximum Bending Angle Research Articles

A Soft Robot for Peripheral Lung Cancer Diagnosis and Therapy.

Lung cancer is one of the deadliest forms of cancers and is often diagnosed by performing biopsies with the use of a bronchoscope. However, this diagnostic procedure is limited in ability to explore deep into the periphery of the lung where cancer can remain undetected. In this study, we present design, modeling, fabrication, and testing of a one degree of freedom soft robot with integrated diagnostic and interventional capabilities as well as vision sensing. The robot can be deployed through the working channel of commercial bronchoscopes or used as a stand-alone system as it integrates a micro camera to provide vision sensing and controls to the periphery of the lung. The small diameter (2.4 mm) of the device allows navigation in branches deeper in the lung, where current devices have limited reachability. We have performed mechanical characterizations of the robotic platform, including blocked force, maximum bending angle, maximum angular velocity, and workspace, and assessed its performance in in vitro and ex vivo experiments. We have developed a computer vision algorithm, and validated it in in vitro conditions, to autonomously align the robot to a selected branch of the lung and aid the clinician (by means of a graphical user interface) during navigation tasks and to perform robot-assisted stabilization in front of a lesion, with automated tracking and alignment.

Structure and function of one-dimensional two-way pneumatic flexible bending joint

In order to solve the problems of comprehensive flexibility of robot arm, and expand the application field of service robot and improve the safety, a one-dimensional two-way flexible bending joint is developed by using the self-developed pneumatic artificial muscle. The relevant theoretical model is established and the relevant experimental analysis is carried out. The experimental results show that the bending joint can realize one-dimensional two-way bending motion and the bending angle of the joint can be controlled by adjusting the gas pressure; when the air pressure difference between the two sides of the leaf spring is 0.22Mpa, the maximum bending angle of the joint reaches 74.12 degrees; the forward and reverse bending of the joint are consistent, and the joint bending curve is similar to the arc.

Design of a novel tendon-driven manipulator structure based on monolithic compliant rolling-contact joint for minimally invasive surgery

PurposeCompliant mechanisms are commonly used in the design of manipulator and surgical robotic tools for minimally invasive surgery (MIS) thanks to their compactness, ability of miniaturization and lower part count. However, conventional compliant joint has higher internal stiffness, which limits the bending radius. To overcome this problem, a novel tendon-driven manipulator structure based on monolithic compliant rolling-contact joint (CRCJ) is proposed.MethodsThe proposed rolling-contact mechanism is used to prevent cable slack during actuation, which occurs in conventional compliant joint design. By means of selective laser sintering (SLS) technique, the CRCJ can be fabricated in a monolithic structure, thus granting the CRCJ both the advantages of compliant joints and rolling-contact mechanism. Simulations with nonlinear finite element analysis (FEA) and experiments were conducted to evaluate and compare the mechanical properties of the proposed CRCJ with conventional leaf-type compliant joint including the bending and compliant motion.ResultsExperimental results showed that the CRCJ has lower bending stiffness, higher maximum bending angle (over 180^{circ }) and a higher compliance compared to conventional compliant hinges, which allows a larger workspace and reduces the possibility of tissue injury. Agreement was also found between the nonlinear FEA and experiments regarding the relation between actuation force and bending angle. A primary prototype of a 3-DOF handheld laparoscopic manipulator with a diameter of 7 mm was further developed.ConclusionA dexterous tendon-driven monolithic manipulator structure based on CRCJ for MIS is proposed. A preliminary prototype of a handheld laparoscopic manipulator demonstrates the capability of the CRCJ for steerable medical devices. However, design improvements based on FEA and application-orientated prototypes considering anatomical requirements still show room for improvements.

Modeling and motion control of an octopus-like flexible manipulator actuated by shape memory alloy wires

Soft robots are concerned by researchers due to several characteristics, such as high adaptability in complex unstructured environments, safe interaction with environments, and a high degree of dexterity. The deformability and dexterity of the octopus arm are remarkable and interesting for the development of bioinspiration soft robots. In this study, we proposed a biomimetic flexible manipulator actuated by shape memory alloy (SMA) wires and its PI controller, and evaluated its performances with focused experiments. This study aims to find out the advantages of the developed manipulator actuated by SMA wires. We designed the bionic structure to achieve flexible bending in 3D space based on the analysis of the octopus muscle structure. Then we built the mathematical models that described the relationship between the bending angle and the driving parameters. Surprisingly, the soft movement capacity of the bionic manipulator was investigated at different heating voltages and PWM duty cycles by the PI controller based on the self-sensing resistance feedback. The soft manipulator was able to bend flexibly with the maximum bending angle of 60°. Compared to the traditional soft arm, the soft manipulator has higher accuracy, with the error of the deflection angle less than 5° and the errors of bending angles less than 2°.

Design and development of Cu–Al–Ni shape memory alloy coated optical fiber sensor for temperature sensing applications

— This paper focuses on the development of copper-based shape memory alloy (SMA) coated optical fiber sensor. The developed sensors are having potential applications for condition monitoring in different systems. The Cu–Al–Ni (82%-14%–4%) SMA has been deposited on optical fiber with the help of flash evaporation. To have an efficient deposition, an in-situ fixture has been designed, which can induce strain and rotate the fiber to get a uniform coating. The samples are prepared by varying the rotational speed of the fixture between 24 and 36 rpm (rotation per minute) during deposition. The optical fiber deposited at a rotational speed of 24 rpm has achieved a maximum bending angle of 53°. The actuation behaviour has been investigated in detail for varying load and voltage. Also, the surface morphology, thickness measurement and thermal analysis of coated and uncoated optical fiber have been investigated in detail. A complete review of test results showing the characteristics and performance of plastic optical fibers after coating with shape memory alloy has been provided in this paper. Static structural analysis has been performed in ANSYS workbench to observe the stress and strain developed during the bending of SMA coated fiber.

Chinese Calligraphy Inspired Design of Humidity/Light Dual Responsive Magic Paper

AbstractPaper flowers are frequently, for example as indoor decorations and in wedding bouquets. But these traditional paper flowers can only maintain static conditions, greatly affecting their sensory effects, vividness, and appreciation. The design of novel paper flowers with dynamic shape deformation could effectively broaden the application of paper flowers. Here, inspired by Chinese calligraphy, a novel polyvinyl butyral (PVB)/carbon/cellulose composite (PCC) magic paper with a sandwiched structure is prepared. The hygroscopicity difference between hydrophobic PVB and hydrophilic cellulose layer endows the PCC paper with humidity responsiveness, and the maximum bending angle is up to 91.4° upon exposure to humidity environment. Carbon in the interlayer with strong light–heat conversion capacity could further accelerate water desorption and deformation speed, resulting in highly sensitive light responsiveness. The recovery time of PCC paper from maximum bending to the original flat state is shorter than 1 s. The PCC paper has good flexibility and processability, which can be cut and assembled into flowers with different shapes, and these unique magic flowers could freely bloom and furl upon external stimulus. All these results indicate that PCC paper has great potential in the production of magic props, artworks, and intelligent household decorations fields.

Research on performance of rigid-hoop-reinforced multi-DOF soft actuator

In order to improve the bearing capacity of soft actuators, this article presents the development of the rigid-hoop-reinforced (spring or steel hoop) multi-DOF soft actuator. The actuator is composed of a rotary module with spring reinforcement on the silicone rubber-based body and a bending module with steel hoop reinforcement on the body. Compared with fiber-reinforced actuators, the bearing capacities of rigid-hoop-reinforced actuators made of 65Mn spring steel are improved. The radial and the axial bearing capacity for the bending module and the rotary module is raised by 29.6%, 28.2%, 30.6%, 49.6% respectively; under the same pressure, the spring-reinforced interval increases the maximum rotary angle of the rotary module, the steel hoop-reinforced interval increases the maximum bending angle of the bending module; with the same reinforcement type, the bending module with reinforcement interval of 10 mm has good bending characteristics that the bending angle changes with the pressure gently; the lower the hardness of silicone rubber base body, the better the adaptability and flexibility of the actuator, and the higher the hardness, the greater the bearing capacity of the actuator. Due to the above advantages, the rigid-hoop-reinforced multi-DOF soft actuator can be applied to medical devices which need high load-carrying capacity.

An Origami-Based Soft Robotic Actuator for Upper Gastrointestinal Endoscopic Applications.

Soft pneumatic actuators have been explored for endoscopic applications, but challenges in fabricating complex geometry with desirable dimensions and compliance remain. The addition of an endoscopic camera or tool channel is generally not possible without significant change in the diameter of the actuator. Radial expansion and ballooning of actuator walls during bending is undesirable for endoscopic applications. The inclusion of strain limiting methods like, wound fibre, mesh, or multi-material molding have been explored, but the integration of these design approaches with endoscopic requirements drastically increases fabrication complexity, precluding reliable translation into functional endoscopes. For the first time in soft robotics, we present a multi-channel, single material elastomeric actuator with a fully corrugated design (inspired by origami); offering specific functionality for endoscopic applications. The features introduced in this design include i) fabrication of multi-channel monolithic structure of 8.5 mm diameter, ii) incorporation of the benefits of corrugated design in a single material (i.e., limited radial expansion and improved bending efficiency), iii) design scalability (length and diameter), and iv) incorporation of a central hollow channel for the inclusion of an endoscopic camera. Two variants of the actuator are fabricated which have different corrugated or origami length, i.e., 30 mm and 40 mm respectively). Each of the three actuator channels is evaluated under varying volumetric (0.5 mls-1 and 1.5 mls-1 feed rate) and pressurized control to achieve a similar bending profile with the maximum bending angle of 150°. With the intended use for single use upper gastrointestinal endoscopic application, it is desirable to have linear relationships between actuation and angular position in soft pneumatic actuators with high bending response at low pressures; this is where the origami actuator offers contribution. The soft pneumatic actuator has been demonstrated to achieve a maximum bending angle of 200° when integrated with manually driven endoscope. The simple 3-step fabrication technique produces a complex origami pattern in a soft robotic structure, which promotes low pressure bending through the opening of the corrugation while retaining a small diameter and a central lumen, required for successful endoscope integration.

Non-solvent phase separation-assisted fabrication for flexible polyacrylonitrile based carbon membrane with excellent mechanical properties

Carbon membranes have great potential for gas separation and water treatment due to their excellent chemical stability and relatively low price. However, current methods used in membrane preparation are very complicated, which largely limits their large-scale applications. Due to this, a fast and feasible non-solvent induced phase separation method, combining with stabilization and carbonization, was provided to fabricate high performance flexible carbon membrane from polyacrylonitrile (PAN) with the presence of N,N-dimethylformamide (non-solvent). The microstructure and performances of all the samples were investigated by SEM, X-ray diffraction (XRD), Raman spectra and FTIR spectra along with fiber strength tester. Results suggested that the microstructure and mechanical properties of carbon membranes could be controlled by thermal treatment conditions. The optimized PAN-based carbon membrane exhibited the best mechanical properties with a tensile strength of 26.41 MPa as well as the maximum bending angle of 180°. Therefore, this research with the non-solvent induced phase separation method could prepare high performance flexible carbon membrane, and provide a new pathway for the preparation of flexible carbon membrane with feasible and fast method.

Miniature Continuum Manipulator With Three Degrees-of-Freedom Force Sensing for Retinal Microsurgery

Abstract Retinal microsurgery requires the precise manipulation of delicate tissue in the interior of the eye. Smart surgical instruments with dexterous tip and force sensing capabilities can permit surgeons to perform more flexible surgical procedures and obtain imperceptible force information, thereby improving the safety and efficiency of microsurgery. In this study, we present an intraocular continuum manipulator with three degrees-of-freedom (DOF) force sensing capabilities. A contact-aided compliant mechanism based on cutting superelastic Nitinol tubes is used to provide high dexterity. It enables two rotational DOFs at the distal end of the manipulator. Fiber Bragg grating (FBG) fibers are used to provide high-resolution force measurements. Moreover, a novel Nitinol flexure was designed to achieve high axial force sensitivity. The experimental results show that the maximum bending angle of the dexterous tip is more than ±45 deg for each DOF with high repeatability. In addition, the experimental results demonstrate that the proposed force sensor can provide sub-millinewton resolution. The manipulator has also been validated with an artificial eye model, demonstrating the potential clinical value of the manipulator for retinal microsurgery.

Nanostructured porous polyaniline (PANI) coated carbon cloth (CC) as electrodes for flexible supercapacitor device

Nanostructured porous polyaniline (PANI) has been synthesized and coated simultaneously on a highly flexible and conductive carbon cloth (CC) substrate using a simple in-situ chemical oxidative polymerization technique. PANI coated CC (PANI−CC) based flexible electrodes were further used for the fabrication of flexible supercapacitor devices. For the comparison purpose, pure PANI has also been synthesized and tested for its electrochemical performance. The energy storage capacity of PANI and PANI–CC composite was investigated using electrochemical techniques like CV, GCD, and EIS in a potential range from 0 to 0.8 V in 1 M H2SO4 electrolyte. PANI−CC flexible electrodes exhibited the highest specific capacitance of 691 F/g; whereas, pure PANI could only achieve 575 F/g of specific capacitance at 1 A/g. Composite also exhibited outstanding cyclic stability by recollecting 94 % of its initial capacitance after 2000 GCD cycles. For actual implementation, a flexible supercapacitor device has been fabricated using stainless steel sheets and PANI−CC flexile electrodes. The energy storage performance of the PANI−CC flexible supercapacitor device was tested at several bending angles, which resulted in 72 % of capacitance retention at a maximum bending angle of 140° compared to the capacitance obtained at an angle 0° (flat state). PANI−CC exhibited improved electrochemical performance than pure PANI due to the synergistic effect between PANI and CC. Here, CC helped in enhancing the conductivity and stability; whereas, PANI boosted the capacitance owing to its excellent porosity and fast pseudocapacitive charge storage response.

A New Extensible Continuum Manipulator Using Flexible Parallel Mechanism and Rigid Motion Transmission

Abstract An extensible continuum manipulator (ECM) has specific advantages over its nonextensible counterparts. For instance, in certain applications, such as minimally invasive surgery or pipe inspection, the base motion might be limited or disallowed. The additional extensibility provides the robot with more dexterous manipulation and a larger workspace. Existing continuum robot designs achieve extensibility mainly through artificial muscle/pneumatic, extensible backbone, concentric tube, and base extension, etc. This article proposes a new way to achieve this additional motion degree-of-freedom by taking advantage of the rigid coupling hybrid mechanism concept and a flexible parallel mechanism. More specifically, a rack and pinion set is used to transmit the motion of the i-th subsegment to drive the (i+1)-th subsegment. A six-chain flexible parallel mechanism is used to generate the desired spatial bending and one extension mobility for each subsegment. This way, the new manipulator can achieve tail-like spatial bending and worm-like extension at the same time. Simplified kinematic analyses are conducted to estimate the workspace and the motion nonuniformity. A proof-of-concept prototype was integrated to verify the mechanism’s mobility and to evaluate the kinematic model accuracy. The results show that the proposed mechanism achieved the desired mobilities with a maximum extension ratio of 32.2% and a maximum bending angle of 80 deg.

A method to 3D print a programmable continuum actuator with single material using internal constraint

Soft continuum robots require differential control of channel pressure across several modules to trace 3D trajectories at the tip. For current designs of such actuators, sheathing is required to prevent radial expansion when the chambers are pressurized. With the recent development of soft materials additive manufacturing, 3D printing has become a promising fabrication method for soft continuum robots. However, most current designs for continuum actuators are based on molding, which are not designed for 3D printing. This paper proposes an internal constraint-based soft continuum actuator for single material 3D printing, with tunable design parameters to render pre-defined motions. The internal constraint method maximizes the superiority of the rapid prototyping solution in terms of customizing the soft continuum actuators with high fabrication speed and design freedom. The internal constraints come in the form of internal beam elements that not only limit the undesired radial expansion (up to ∼14% of conventional design) but also allows the actuator to be pressurized at a higher driving pressure (up to ∼160%) and higher maximum bending angle (up to ∼320%) compared to conventional no-beam design. By tuning the design parameter q (determined by the number of constraint beams n per radial cross-section and the number of such sections k along the axial direction), we can render the actuator to the desired movement under specific driving pressure p. We show numerical simulation and hardware experiment results for a soft actuator to achieve specified bending and twisting motions following this design approach.

A Gas-Ribbon-Hybrid Actuated Soft Finger with Active Variable Stiffness.

A new hybrid actuated soft finger with active variable stiffness is proposed for the first time by integrating gas-driven and ribbon-driven mechanisms. By carefully coordinating the two mechanisms, the bending deformation and the stiffness modulation processes of the soft finger can be uncoupled, providing it with both high flexibility and good variable stiffness. Although the soft finger, made entirely from flexible materials, works under a low and safe gas pressure of below 35 kPa, the maximum bending angle reaches ∼210°, and a single soft finger can withstand a weight of 1.25 kg. For any bending angle, with the help of the ribbon-driven mechanism, the stiffness of the soft finger can increase by three to six times. In addition, theoretical models are established for the evaluation of the bending-deformation characteristic and the output force of the soft finger, which are verified by experiments. A dual-finger soft robotic gripper is assembled by utilizing two soft fingers, which can easily and stably grab various objects with different sizes, shapes, and weights. Both the theoretical and experimental results indicate that the proposed gas-ribbon-hybrid actuated mechanism can effectively enhance the variable stiffness property of a soft finger while retaining its good compliance with the surroundings. This work might provide future insights for the development of compact and cost-effective soft end effectors with active variable stiffness.

Flexible PTFE/MXene/PI soft electrothermal actuator with electromagnetic-interference shielding property

In recent years, soft electrothermal actuators (ETAs) have attracted great concern because of their potential applications in biomimetic intelligent devices, soft robotics and aerospace engineering. However, achieving the simultaneous optimization of low-voltage actuation, ultrafast preparation and highly integrated functionality are main challenges to the development of ETAs. Herein, a flexible, hydrophobic, mechanically robust and electromagnetic-interference (EMI) shielding PTFE/MXene/PI soft ETA is constructed through a very simple and fast “cutting and sticking” method by taping PTFE and PI tapes onto the surface of MXene film. The commercially available PTFE and PI tapes endow PTFE/MXene/PI sandwich structure with ideal mechanically robustness and hydrophobic self-cleaning function, thus it can work in different environments. Remarkably, PTFE/MXene/PI sandwich structure shows an outstanding EMI shielding ability with the maximum SET value of 44 dB owing to the high electrical conductivity of MXene film. More importantly, the PTFE/MXene/PI sandwich actuator can bend from PTFE side toward PI side under the electrical stimulus, because the excellent electrothermal MXene layer is sandwiched between the two tapes with large difference in thermal expansion coefficients. Under a 6 V low voltage, the actuator can generate heat energy with the maximum saturation temperature of 110 °C and large bending deformation with the maximum bending angle of 122° within 40 s. Interestingly, the PTFE/MXene/PI structure can be designed and manufactured in different shapes and configurations upon actuation, such as the “S” shape and four-finger gripper. At last, a smart shielding curtain with the combination of actuation properties and EMI shielding performance is finally developed as a principle of concept, which further indicates the multifunctional PTFE/MXene/PI ETA can be widely applied in smart EMI shielding system and soft robotic devices.

Preparation, property manipulation and application of ɑ-cyanostilbene-containing photoresponsive liquid crystal elastomers with different alkoxy tail length

Photoresponsive liquid crystal elastomers have aroused wide attention due to their unique structure and properties. Most of the reported photoresponsive liquid crystal elastomers were prepared using azobenzene as photoresponsive group. There are few kinds of photoresponsive groups that can be used to construct photoresponsive liquid crystal elastomers directly. It is of great significance to develop photoresponsive liquid crystal elastomers based on new photoresponsive group and investigate the relationship between chemical structure and its properties. Herein, we reported a series of physically cross-linked photoresponsive liquid crystal elastomers with different alkoxy tail lengths (abbreviated as LCE-PM10PVPCm, m = 4, 8, 12, 16) using α-cyanostilbene as photoresponsive mesogens. The phase structure of the polymers, the photo-induced deformation property and the application of the LCE-PM10PVPCm fibers were thoroughly studied. The results show that LCE-PM10PVPCm with different alkoxy tail length show smectic phase. With increasing of alkoxy tail length, the glass transition temperature decreases while the clearing point temperature generally shows an increasing trend. The uniaxially oriented LCE-PM10PVPCm fibers also show a large bending angle and fast photoresponse speed when exposed to 365 nm UV light. The maximum bending angle of LCE-PM10PVPC4 can achieve 113°, and the maximum bending angle decreases with the increase of alkoxy tail length. We also discussed the mechanism of this bending behavior, which is mainly attributable to trans–cis isomerization and the photothermal effect of α-cyanostilbene. Besides, cis α-cyanostilbene possesses excellent thermal stability, which endows the photoresponsive liquid crystal elastomers with application in information encryption materials.

Electro-thermo-mechanical modelling of micro solar sails of chip scale spacecraft in space

This paper presents a novel design of micro solar sails for emerging lightweight chip scale spacecraft based on flexible electronic circuits. To acquire large deformation, the micro solar sails were designed to be bilayer beams that were able to be electro-thermally actuated by Joule heating. The concept design of the solar sail with high area-to-mass ratios allowed the solar sailing system, named as ChipSail, for efficient orbital transfer and attitude adjustment. The principle of solar sailing with ChipSail was illustrated, and the thickness of the two metals for the bilayer sails should be no more than 1 µm, so as to achieve the efficient solar sailing. Then, the fabrication and characterization of such bilayer microstructures for solar sails were introduced briefly. After that, the electro-thermal analysis of such solar sails deployed on the low earth orbit was carried out, and it was found that the balanced temperature of the sails under the effect of solar radiation and thermal reemission of the sails was 315.31 K, followed by electro-thermal modelling of the sails under the Joule heating. A nonlinear second order differential equation was derived, which allowed rapid prediction of the thermal distribution across the sail. Equivalence of the bilayer solar sail to a width-changing 980 µm long bilayer beam was proposed and validated by finite element analysis. Finally, the thermo-mechanical model on the bilayer sail was then established and solved numerically. Results showed that the maximum bending angle could reach to 94.05o by applying a voltage of 0.05 V across the sail. The electro-thermo-mechanical model laid a solid foundation for dynamic control of the configuration of the ChipSail for efficient orbital transfer and attitude adjustment in space.

Multiple hydrogen-bonded cross-linked photo-responsive liquid crystal elastomers with photo-responsive fluorescence

Luminescent liquid crystal elastomers (LCEs) have wide application prospect in fluorescent soft actuators and dynamic display devices. α-Cyanostilbene shows a rigid rod structure, aggregation-induced emission enhancement (AIEE) characteristic and photo-induced trans-cis isomerization, which can be used as multifunctional building block to prepare stimulus responsive luminescent LCEs. In this paper, a series of physically cross-linked luminescent LCEs showing photo-induced deformation behavior and photo-responsive fluorescence are obtained (named as LCE-M(x)-L(y), x and y denote the feed mole fraction of M6PVPC10 and ME6UPy respectively, x + y = 1, y = 0.04, 0.06, 0.08, 0.10, 0.12). The photo-induced deformation, luminescent property, and the intrinsic relationship between the luminescent behavior and the photo-induced bending behavior of LCEs were studied in particular. Under the irradiation of 365 nm ultraviolet light, the prepared uniaxially oriented LCEs bent toward the direction of light. The deformation rate, the maximum bending angle of polymers are sensitive to crosslinking agent content, and increase with increasing crosslinking agent content. All the prepared LCEs also behave AIEE characteristic and can emit strong fluorescence in solid state. Meanwhile, LCE-M(x)-L(y) presents stimuli-sensitive fluorescence, and the emission intensity decreases with increasing of 365 nm UV light irradiation time. The emission intensity variation with 365 nm UV irradiation is proved to be related to the photo-induced deformation, which can be used to monitor the deformation of LCEs.

Downplaying the role of water in the rheological changes of conducting polymers by using water-in-salt electrolytes.

Volumetric changes associated with solvent/electrolyte exchange in electronic conducting polymers (ECPs) play an important role in the mechanical stability of the polymers, as these changes are a critical factor in ECP-based energy storage devices. Thus, the present work explores the hindering of such volumetric deformations for polypyrrole films doped with dodecylbenzenesulphonate (PPy(DBS)) by employing highly concentrated aqueous electrolytes (or water-in-salt electrolytes, WiSEs), and their effects over the corresponding electrochemical capacitor cell energy retention. Electrochemical quartz crystal microbalance with dissipation monitoring measurements for thin PPy(DBS) films in the WiSEs revealed negligible dissipation changes (ΔDn ≈ 0), in contrast with those in dilute aqueous electrolyte (ΔDn ≠ 0), indicating inexpressive structural deformation of PPy(DBS) in the WiSE. This phenomenon is observed for thick freestanding PPy(DBS) films, which presented a maximum bending angle decay from ∼56° (diluted aqueous electrolyte) to 3.5° when working in the WiSE, thus proving the hindering of film bending. The observed trends are reflected in the PPy(DBS) cell energy retention, where the use of a WiSE decreased cell energy fading by 30% after 600 cycles, in comparison with cells based on diluted electrolytes.

Fully 3D-Printed Modular Pipe-Climbing Robot

In industrial production, current pipe-climbing robots can replace humans in real-time monitoring, leak inspection, and other tasks. However, most pipe-climbing robots are designed for specific applications with complex structures; this limits the adaptability to various conditions. To solve this issue, this letter presents a one-piece 3D-printed pipe-climbing robot composed of sequenced novel soft bending mechanisms. The mechanisms use the small strains of soft materials to achieve large bending deformation. The proposed robot is highly adaptable to pipes with various diameters, radii of curvature, inclinations, and even outer/inner walls because of modular grippers and an inchworm inspired middle section. The good strength and flexibility of the robot are simultaneously achieved by reasonable structural design using one material. In this letter, the design concept and processing methods are introduced. The finite element method is adopted to predict the maximum bending angle of modules to aid design, and a torque test bench is built to acquire output torque and restoring torque. Then, the model of the entire robot is built to facilitate specialized design. Finally, several experiments are conducted to verify the good adaptability of the robot to pipes of various diameters (18-36 mm), inclinations (0-90°, even horizontal pipes), and radii of curvature (minimum to 19 mm). The static bearing ability of the robot reaches 1000g (without climbing at 7 bar, 22 mm diameter vertical pipes), which is almost 80 times its weight. In addition, the load-bearing ability of the robot while climbing on pipes in various states is obtained.