Soft Objects Research Articles

CHINA'S CULTURAL SOFT POWER IN BANGLADESH: ACHIEVEMENTS AND CHALLENGES (2000-2020).

ABSTRACT
 Cultural dominance is one of the most significant aspects of soft power strategy in global politics. The most influential countries employ cultural soft power to consolidate their positions on international platforms to enhance national interests. This study explores China's cultural soft power strategies in Bangladesh by examining its achievements and challenges. It identifies that China has extended its cultural dynamics to considerable levels in Bangladesh, including arranging cultural programs and festivals, exchange programs, support for higher education, cultural institutes, media, availability of cultural content, and infrastructure development. However, China faces several challenges in achieving its soft power objectives due to cultural barriers, political manipulation, and proper management of facilities. This study recommends that China should develop initiatives to reduce the challenges in the country. This study followed a qualitative research method, based on secondary sources. This study fills a crucial gap in the understanding of China's efficacy in Bangladesh. A comprehensive insight into China's cultural soft power will help policymakers in enhancing bilateral relations as well as contribute to academia such as international relations, diplomacy and other intellectual horizons related to Bangladesh studies.
 
 
 
 Keyword: Cultural Soft Power, goals, China, Bangladesh

Structural aspects of the Brazilian experience in international broadcasting

International broadcasting services are typically designed to serve public diplomacy and soft power objectives. Traditionally, Western powers have explored and benefited from this state-sponsored media category. However, countries in the Global South, like Brazil, have endeavoured to establish cross-border television services to bolster their international presence. This paper scrutinizes TV Brasil Internacional as a case study, examining its designated functions, management, and funding models. The research illuminates through document surveys and semi-structured interviews that while the channel initially reflected Brazil’s external policies and public service ideals, structural alterations enabling increased governmental intervention alongside budget cuts rendered the international service dormant.

Programming Motion into Materials Using Electricity-Driven Liquid Crystal Elastomer Actuators.

As thermally driven smart materials capable of large reversible deformations, liquid crystal elastomers (LCEs) have great potential for applications in bionic soft robots, artificial muscles, controllable actuators, and flexible sensors due to their ability to program controllable motion into materials. In this article, we introduce conductive LCE actuators using a liquid metal electrothermal layer and a polyethylene terephthalate substrate. Our LCE actuators can be stimulated at low currents from 2 to 4 A and produce a maximum work density of 9.4 . We illustrate the potential applications of this system by designing a palm-activated artificial muscle gripper, which can be used to grasp soft objects ranging from 5 to 55 mm in size, and even ring-shaped workpieces with precise external or internal support. Furthermore, inspired by the movement of fruit fly larvae, we designed a new soft robot capable of bioinspired crawling and turning by inducing anisotropic friction with an asymmetric design. Finally, we illustrate advanced motional control by designing an autonomously rotating wheel based on the asymmetric contraction of its spokes. To assist in the production of autonomously moving robots, we provide a thorough characterization of its motion dynamics.

LLM for Differentiable Soft Robotic Vision Objects Manipulation

Most existing neural soft object manipulation systems rely on differentiable simu- lation as the default physics engine. However, current explicit differentiable sim- ulation solvers adopt a heuristic searching approach to manipulate the soft body, which easily gets stuck when the initial stage of the end effectors is sub-optimal on single-stage tasks or when performing multi-stage tasks that require complex hi- erarchical actions, which often leads to local-minima. Furthermore, existing deep soft object manipulation systems never consider the soft multi-body dynamics and model the dynamic system with naive explicit visual cues (e.g., image frame). To address this challenge, we propose an implicit, i.e., with energy-based models, soft objects manipulation differentiable simulator (iDSoftor) that guides the dif- ferentiable physics solver to deform the various soft object. The key idea of our work is to integrate energy-based models into the soft-object differentiable simu- lation to address the local minima in common explicit (heuristic transport-based) methods to stabilize the gradient of training differentiable simulators. On simple tasks, such as one-stage tasks, our proposed method can feasibly find a suitable initial stage based on theoretical arguments, refer to. On complex multi-stage tasks with multimodal, like implicit visual cues states, our proposed methods can iteratively adjust the manipulation trajec- tory from the perspective of energy priorities. To evaluate the feasibility of our proposed method, we formulate various potential novel soft-object manipulation tasks and demonstrate a preliminary story.

Impact of coating particles on liquid marble lifetime: reactor engineering approach to evaporation.

Liquid marbles are soft matter objects characterised by a liquid droplet enclosed within a hydrophobic particle coating, preventing wetting. This distinctive structure serves as active sites for solid-liquid-gas reactions. However, the impact the chosen coating material has on liquid marble stability, particularly regarding the number of coating layers and material wetting, remains uncertain. There is a need for a modelling approach to predict the overall lifetime considering these coating characteristics. This study reveals that for PTFE liquid marbles evaporating at ambient temperature, smaller coating particles (250 nm) extend their lifetime by forming a multilayered coating. Conversely, using larger particle sizes (200 μm) results in the formation of monolayer liquid marbles with shorter lifetimes than their equivalent naked droplets. Additionally, a higher number of particle layers and a larger contact angle generally enhance the liquid marble's lifetime. For multilayered liquid marbles comprised of smaller particles (250 nm), the particle contact angle is found to have a more significant impact than the number of layers on lifetime extension, whereas the opposite holds true for larger particle sizes (20 μm). A modelling approach using the reactor engineering method for liquid marble evaporation demonstrates excellent agreement with experimental results, yielding an R2 of 0.996. The implementation of this specific model, capable of assessing lifetime across various physical modifications, will enhance our understanding of liquid marble properties before their application in biomedical, microreactor, and green technologies.

Imitation learning by state-only distribution matching

Imitation Learning from observation describes policy learning in a similar way to human learning. An agent’s policy is trained by observing an expert performing a task. Although many state-only imitation learning approaches are based on adversarial imitation learning, one main drawback is that adversarial training is often unstable and lacks a reliable convergence estimator. If the true environment reward is unknown and cannot be used to select the best-performing model, this can result in bad real-world policy performance. We propose a non-adversarial learning-from-observations approach, together with an interpretable convergence and performance metric. Our training objective minimizes the Kulback-Leibler divergence (KLD) between the policy and expert state transition trajectories which can be optimized in a non-adversarial fashion. Such methods demonstrate improved robustness when learned density models guide the optimization. We further improve the sample efficiency by rewriting the KLD minimization as the Soft Actor Critic objective based on a modified reward using additional density models that estimate the environment’s forward and backward dynamics. Finally, we evaluate the effectiveness of our approach on well-known continuous control environments and show state-of-the-art performance while having a reliable performance estimator compared to several recent learning-from-observation methods.

Development of a method for attaching thin films to curved surfaces using a bipolar electrostatic chuck with a collective beam structure

A bipolar electrostatic chuck (ESC) having a collective beam structure is getting attention as an effective device for handling thin, soft dielectric objects such as polymer film or paper. It has been shown that the ESC devices can grasp and attach thin film objects on a plane. However, the feasibility of pasting films on curved surfaces was not verified. Accurate film attachment requires a designated attachment trajectory so that the thin film does not slide on the curved surface. The trajectory determination depends on how the stiffness of the beam and thin film, the frictional force between the beam and thin film, and electrostatic force affect the attachment process. This study aims at developing a method for calculating the attachment trajectory by modelling the beam of the electrostatic device and thin film as a continuum model consisting of springs and masses. The model's validity was verified by comparing the results with experimental data, and the feasibility of attaching a thin film to a curved surface using an ESC having a collective beam structure was clarified.

Peristaltic transporting device inspired by large intestine structure

A pneumatic large intestine-like soft robot with McKibben muscles is designed based on traveling wave motion. The robot consists of four sections, and each section is controlled by axial and circular muscles independently. The robot can propagate traveling waves inspired by the large intestine’s peristaltic wave, defined by the wavelength and delay of the axial and circular muscles’ supplied air signals. This motion can transport the object in the inner cavity of the robot, making the maximum Transport Capacity Index of 0.069 (with an actual speed of 0.77 mm/s). This study investigates the effect of different parameters of traveling waves generated by axial and circular muscles independently on the ability of a robot to transport the object. Various combinations of traveling waves will lead to different transport directions and speeds of the object and provide more possibilities for selecting control patterns. Furthermore, the proposed robot not only demonstrates effective transportation capabilities for solid objects, but it also has the capacity to transport soft objects. This study can provide new ideas for animal tubular organ bioinspired device design and prototype design references for medical teaching tools.

Transit Time Theory for a Droplet Passing through a Slit in Pressure-Driven Low Reynolds Number Flows.

Soft objects squeezing through small apertures are crucial for many in vivo and in vitro processes. Red blood cell transit time through splenic inter-endothelial slits (IESs) plays a crucial role in blood filtration and disease progression, while droplet velocity through constrictions in microfluidic devices is important for effective manipulation and separation processes. As these transit phenomena are not well understood, we sought to establish analytical and numerical solutions of viscous droplet transit through a rectangular slit. This study extends from our former theory of a circular pore because a rectangular slit is more realistic in many physiological and engineering applications. Here, we derived the ordinary differential equations (ODEs) of a droplet passing through a slit by combining planar Poiseuille flow, the Young-Laplace equations, and modifying them to consider the lubrication layer between the droplet and the slit wall. Compared to the pore case, we used the Roscoe solution instead of the Sampson one to account for the flow entering and exiting a rectangular slit. When the surface tension and lubrication layer were negligible, we derived the closed-form solutions of transit time. When the surface tension and lubrication layer were finite, the ODEs were solved numerically to study the impact of various parameters on the transit time. With our solutions, we identified the impact of prescribed pressure drop, slit dimensions, and droplet parameters such as surface tension, viscosity, and volume on transit time. In addition, we also considered the effect of pressure drop and surface tension near critical values. For this study, critical surface tension for a given pressure drop describes the threshold droplet surface tension that prevents transit, and critical pressure for a given surface tension describes the threshold pressure drop that prevents transit. Our solutions demonstrate that there is a linear relationship between pressure and the reciprocal of the transit time (referred to as inverse transit time), as well as a linear relationship between viscosity and transit time. Additionally, when the droplet size increases with respect to the slit dimensions, there is a corresponding increase in transit time. Most notably, we emphasize the initial antagonistic effect of surface tension which resists droplet passage but at the same time decreases the lubrication layer, thus facilitating passage. Our results provide quantitative calculations for understanding cells passing through slit-like constrictions and designing droplet microfluidic experiments.

Shear-Pressure Decoupling and Accurate Perception of Shear Directions in Ionic Sensors by Analyzing the Frequency-Dependent Ionic Behavior.

In artificial tactile sensing, to emulate the human sense of touch, independent perception of shear force and pressure is important. Decoupling the pressure and shear force is a challenging task for ensuring stable grasping manipulation for both soft and brittle objects. This study introduces a deformable ion gel-based tactile sensor that is capable of distinguishing pressure from shear force when pressurized shear force is applied in any direction. Recognition of the decoupled forces and precise shear directions is enabled by acquiring tactile data at only two frequencies (20 Hz and 10 kHz) based on the frequency-dependent ion dynamics. This study demonstrates monitoring the changes in pressure, shear force, and shear directions while performing practical robotic actions, such as pouring a water bottle, opening a water bottle cap, and picking up a book and placing it on a shelf.

A Broad Range Triboelectric Stiffness Sensor for Variable Inclusions Recognition

HighlightsWe propose a broad range triboelectric sensor system employing elastic sponge and shielding layers, which can realize fast stiffness recognition within 1.0 s at a low cost.A novel algorithm is proposed for rapid stiffness identification by extracting signal characteristics, effectively reducing demand of computing resources.The proposed sensor system can identify the multi-layer stiffness structure of objects, enabling effective recognition of variable inclusions in soft objects with an accuracy of 99.7%.

Fluid-Elastic Interactions Near Contact at Low Reynolds Number

Interactions between fluid flow and elastic structures are important in many naturally occurring and engineered systems. This review collects and organizes recent theoretical and experimental developments in understanding fluid-structure interactions at low Reynolds numbers. Particular attention is given to the motion of objects moving in close proximity to deformable soft materials and the ensuing interplay between fluid flow and elastic deformation. We discuss how this interplay can be understood in terms of forces and torques, and harnessed in applications such as microrheometry, tribology, and soft robotics. We then discuss the interaction of soft and wet objects close to contact, where intermolecular forces and surface roughness effects become important and are sources of complexity and opportunity.

Neural network-based variable stiffness impedance control for internal/external forces tracking of dual-arm manipulators under uncertainties

The desired interaction between manipulators, objects, and environments has resulted in the internal/external force control for dual-arm manipulators being in increasing demand. Consequently, this study focused on the internal/external force tracking for dual-arm manipulator systems under external disturbances, geometries, and stiffness uncertainties which continuously lead to unsatisfactory internal force tracking. The proposed scheme is based on a two-level adaptive impedance control scheme, where the stiffness coefficient is adjusted to adapt to uncalibrated objects. An object-level hybrid impedance controller was used to regulate the external disturbance to produce a compliant response. A manipulator-level neural network-based variable stiffness impedance controller (NNVSIC) was proposed to regulate the internal force under various uncertainties. Additionally, an adaptive wavelet neural network was designed to compensate for the geometric estimation errors of the object. The variable stiffness coefficient could automatically adapt to an unknown object during the cooperation process. One advantage of the proposed method is that no prior knowledge was required. The same controller parameters could be adapted to various objects. The asymptotic stability of the proposed NNVSIC was proven via Lyapunov stability analysis. A series of experiments were conducted using two self-developed nine-degrees-of-freedom redundant manipulators. Furthermore, hard and soft objects of various geometries and stiffnesses were used to verify the effectiveness of the algorithm. The experimental results demonstrated the efficiency and superiority of the proposed controller through performance comparison with various algorithms.

Inconsistency Between Pictures on Baby Diaper Packaging in Europe and Safe Infant Sleep Recommendations

To describe the level of inconsistency between pictures on baby diaper packaging and safe infant sleep recommendations (SISRs) in Europe. We attempted to identify all packaging of baby diapers sold in 11 European countries for infants weighing less than 5 kg through internet searches from July 2022 through February 2023. For each type of package, we extracted whether there was a picture depicting a baby, whether the baby was sleeping, and whether the picture of the sleeping baby was inconsistent with ≥1 of 3 SISRs: (i) non-supine sleeping position, (ii) soft objects or loose bedding, or (iii) sharing a sleep surface with another person. Data were aggregated at the country level, and a random-effects meta-analysis of proportions was used to obtain summary estimates. The outcome was the summary estimate of the proportion of pictures that were inconsistent with SISRs. We identified 631 baby diaper packaging types of which 49% (95% confidence interval CI: 42-57; N=311) displayed a picture of a sleeping baby. Among those 311 packages, 79% (95% CI 73-84) were inconsistent with ≥1 SISR, including a non-supine sleeping position, 45% (95% CI 39-51), soft objects or loose bedding such as pillows or blankets, 51% (95% CI 46-57), and sharing a sleep surface with another person, 10% (95% CI 4-18). Pictures on baby diaper packaging in Europe are often inconsistent with SISRs. The prevention of sudden unexpected death in infancy requires action from manufacturers and legislators to stop parents' exposure to misleading images that may lead to dangerous practices.

An Empirical Comparison of Moderated and Unmoderated Gesture Elicitation Studies on Soft Surfaces and Objects for Smart Home Control

Conducting gesture elicitation studies (GES) in personal spaces such as smart homes is crucial to achieving high ecological validity of elicited gestures. However, supervising such studies is considered intrusive and negatively affects the results' quality. The alternative is to conduct unsupervised GES under similar conditions, but more side-by-side comparisons documenting the similarities and differences between both approaches are necessary. Consequently, we need more data describing the preferred approach and whether the differences or similarities in the results are so significant to cause concern. This research distributed a DIY observation kit, which 30 participants assembled and used to propose gestures for controlling elements in a smart living room using a pillow's surface, with and without supervision. Our results show that gestures from supervised and unsupervised studies differ in quantity and max-consensus but not in gesture Agreement Scores. Our results also show that participants preferred conducting unsupervised studies but proposed fewer gesture sets in this condition.

Modeling Contact Stiffness of Soft Fingertips for Grasping Applications.

Soft fingertips have distinct intrinsic features that allow robotic hands to offer adjustable and manageable stiffness for grasping. The stability of the grasp is determined by the contact stiffness between the soft fingertip and the object. Within this work, we proposed a line vector representation method based on the Winkler Model and investigated the contact stiffness between soft fingertips and objects to achieve control over the gripping force and fingertip displacement of the gripper without the need for sensors integrated in the fingertip. First, we derived the stiffness matrix of the soft fingertip, analyzed the contact stiffness, and constructed the global stiffness matrix; then, we established the grasp stiffness matrix based on the contact stiffness model, allowing for the analysis and evaluation of the soft fingertip's manipulating process. Finally, our experiment demonstrated that the variation in object orientation caused by external forces can indicate the contact force status between the fingertip and the object. This contact force status is determined by the contact stiffness. The position error between the theoretical work and tested data was less than 9%, and the angle error was less than 5.58%. The comparison between the theoretical contact stiffness and the experimental results at the interface indicate that the present model for the contact stiffness is appropriate and the theoretical contact stiffness is consistent with the experiment data.

UKRAINIAN ACADEMY OF PEDIATRIC SPECIALTIES (UAPS) EUROPEAN SLEEP MEDICINE AND NEUROPHYSIOLOGY ASSOCIATION (ESMANA) STATEMENT OF THE ON SAFE SLEEP AS A PRIORITY ISSUE IN THE PREVENTION OF SUDDEN INFANT DEATH SYNDROME

Sudden infant death syndrome (SIDS) remains a pressing issue worldwide, with a significant number of cases occurring within the first six months of life. Many of these tragedies can be prevented by adhering to safe sleep guidelines. The effectiveness of large-scale educational programs focusing on these guidelines has been well-documented in developed countries, resulting in the saving of thousands of children's lives.In Ukraine, there are currently no national guidelines for the prevention of SIDS. To address this gap, we have compiled modern guidelines from other countries such as the USA, Great Britain, and Germany, along with the latest research data, to develop recommendations for safe sleep practices for children under one year of age. These recommendations cover various aspects, including the recommended sleep position (on the back), requirements for the sleeping surface and crib, suggestions for safe co-sleeping, and guidelines for maintaining an appropriate temperature. We also provide information on the beneficial effects of breastfeeding and vaccination in preventing SIDS, as well as the increased risks associated with overheating, the presence of soft objects near a sleeping child, and parental smoking and alcohol consumption.These recommendations should be disseminated to both parents and healthcare professionals involved in infant care.

Micro-adhesive structure inspired by tree frog toe pads fabricated by femtosecond laser processing of PVA sponge

Tree frogs of the species Zhangixalus arboreus are known to generate high adhesive force in wet environments due to the microstructure of their toe pads. Inspired by this toe pads, we fabricated a micro-adhesive structure with hexagonal channels (500, 375, 250, 188, and 125 μm per side) on the surface of a polyvinyl alcohol sponge. Femtosecond laser processing was used to create fine grooves on the surface of the sponge. When the sponge is pressed against the object, the liquid in the sponge is released onto the contact surface. In wet conditions, it is important to maintain the proper thickness of the liquid phase between the microstructure and the object, and this is achieved by the sponge. The characteristics of friction (shear force) between soft and hard objects differ from those between hard materials. When the liquid present on the contact surface is very small, the surface tension of the liquid phase causes the formation of numerous microcapillary bridges, which generate shear forces. The shear force was evaluated by soaking the sponge with water, pressing (300, 400, 500 μm) a flat or uneven surface against the sponge, and then sliding (20, 40 mm/s) the object. The maximum shear force was 0.22 N for the flat surface and 0.34 N for the uneven surface. It was found that the shear force became smaller when the structure became too fine. This phenomenon is due to the agglomeration of the microstructures.

Grasping Profile Control of a Soft Pneumatic Robotic Gripper for Delicate Gripping

Soft pneumatic grippers (SPGs) have garnered significant attention and recognition in various industries owing to their remarkable flexibility, safety, and adaptability. They excel in manipulating delicate, irregularly shaped, and soft objects, surpassing the limitations of conventional grippers. However, effective control techniques for managing the grasping profile of SPGs are still under development. Simple on–off pressure control using a regulator valve is inadequate for delicate gripping with pneumatic robot grippers. To address this, a synergy pressure control system was implemented. In addition, a proportional–integral–derivative control technique, complemented by an unknown input observer, was devised to control the volume of the soft pneumatic robotic gripper, ensuring its alignment with the desired volume level. The simulation and experimental results provide substantial evidence of the effectiveness of the developed control technique and the unknown input observer in managing the volume and pressure of the gripper. Consequently, this breakthrough empowers precise and delicate gripping actions, enabling the handling of delicate objects such as tofu.

From CAD Models to Soft Point Cloud Labels: An Automatic Annotation Pipeline for Cheaply Supervised 3D Semantic Segmentation

We propose a fully automatic annotation scheme that takes a raw 3D point cloud with a set of fitted CAD models as input and outputs convincing point-wise labels that can be used as cheap training data for point cloud segmentation. Compared with manual annotations, we show that our automatic labels are accurate while drastically reducing the annotation time and eliminating the need for manual intervention or dataset-specific parameters. Our labeling pipeline outputs semantic classes and soft point-wise object scores, which can either be binarized into standard one-hot-encoded labels, thresholded into weak labels with ambiguous points left unlabeled, or used directly as soft labels during training. We evaluate the label quality and segmentation performance of PointNet++ on a dataset of real industrial point clouds and Scan2CAD, a public dataset of indoor scenes. Our results indicate that reducing supervision in areas that are more difficult to label automatically is beneficial compared with the conventional approach of naively assigning a hard “best guess” label to every point.