Multi-dimensional microfluidic paper-based analytical devices (μPADs) for noninvasive testing: A review of structural design and applications.

The rapid emergence of microfluidic paper-based devices as point-of-care testing (POCT) tools for early disease diagnosis and health monitoring, particularly in resource-limited areas, holds immense potential for enhancing healthcare accessibility. Leveraging the numerous advantages of paper, such as capillary-driven flow, porous structure, hydrophilic functional groups, biodegradability, cost-effectiveness, and flexibility, it has become a pivotal choice for microfluidic substrates. The repertoire of microfluidic paper-based devices includes one-dimensional lateral flow assays (1D LFAs), two-dimensional microfluidic paper-based analytical devices (2D μPADs), and three-dimensional (3D) μPADs.

Design and Synthesis of a Robust and Multifunctional Superhydrophobic Coating with a Three-Dimensional Network Structure on a Paper-Based Material.

A fundamental challenge in artificial superhydrophobic papers is their poor resistance to mechanical abrasion, which limits their practical application in different fields. Herein, a robust and multifunctional superhydrophobic paper is successfully fabricated via a facile spraying method by combining silver nanowires and fluorinated titania nanoparticles through a common paper sizing agent (alkyl ketene dimer) onto paper. It is shown that the surface of the paper-based material presents a three-dimensional network structure due to the cross-linking of silver nanowires with a high aspect ratio.

A novel process for efficient utilization of bamboo fiber resource in dissolving pulp production by fiber fractionation: Laboratory study and mill trials.

The rational use of bamboo to make dissolving pulp can offer up new opportunities for cellulose production, alleviating wood scarcity. Bamboo contains a high content of non-fiber cells, which presents technical challenges in dissolving pulp production by the conventional process. In this study, a process concept of separating hemicelluloses is presented by fiber fractionation and purification for cleaner production of bamboo dissolving pulp: bamboo kraft pulp was fractionated into long-fiber and short-fiber fractions.

Biomechanical Consequences of Walking With the Suspended Backpacks.

Objective: This article aimed to investigate the biomechanical mechanisms underlying the energetic advantages of the suspended backpacks during load carriage.

Methods: In this study, we examined eight adults walking with a 15 kg load at 5 km/h with a designed suspended backpack, in which the load could be switched to locked and suspended with four combinations of stiffness. Mechanical work and metabolic cost were measured during load carriage.

A Probability Fusion Approach for Foot Placement Prediction in Complex Terrains.

Prediction of foot placement presents great potential in better assisting the walking of people with lower-limb disability in daily terrains. Previous researches mainly focus on foot placement prediction in level ground walking, however these methods cannot be applied to daily complex terrains including ramps, stairs, and level ground with obstacles. To predict foot placement in complex terrains, this paper presents a probability fusion approach for foot placement prediction in complex terrains which consists of two parts: model training and foot placement prediction.

Neural Correlation of EEG and Eye Movement in Natural Grasping Intention Estimation.

Decoding the user's natural grasp intent enhances the application of wearable robots, improving the daily lives of individuals with disabilities. Electroencephalogram (EEG) and eye movements are two natural representations when users generate grasp intent in their minds, with current studies decoding human intent by fusing EEG and eye movement signals. However, the neural correlation between these two signals remains unclear.

An Intelligent Rehabilitation Assessment Method for Stroke Patients Based on Lower Limb Exoskeleton Robot.

The 6-min walk distance (6MWD) and the Fugl-Meyer assessment lower-limb subscale (FMA-LE) of the stroke patients provide the critical evaluation standards for the effect of training and guidance of the training programs. However, gait assessment for stroke patients typically relies on manual observation and table scoring, which raises concerns about wasted manpower and subjective observation results. To address this issue, this paper proposes an intelligent rehabilitation assessment method (IRAM) for rehabilitation assessment of the stroke patients based on sensor data of the lower limb exoskeleton robot.

UV and IR dual light triggered cellulose-based invisible actuators with high sensitivity.

Actuators are widely used in bionic devices and soft robots, among which invisible actuators have some unique applications, including performing secret missions. In this paper, highly visible transparent cellulose-based UV-absorbing films were prepared by dissolving cellulose raw materials using N-methylmorpholine-N-oxide (NMMO) and using ZnO nanoparticles as UV absorbers. Furthermore, transparent actuator was fabricated by growing highly transparent and hydrophobic polytetrafluoroethylene (PTFE) film on regenerated cellulose (RC)-ZnO composite film.

Adaptive Oscillator-Based Assistive Torque Control for Gait Asymmetry Correction With a nSEA-Driven Hip Exoskeleton.

Gait asymmetry is an important clinical characteristic of the hemiplegic gait most stroke survivors suffered, leading to restricted functional mobility and long-term negative impact on their quality of life. In recent years, robot assistance has been proven able to improve stroke patients' functional walking, but few studies have been conducted to specifically correct gait asymmetry of stroke patients during the whole gait cycle. In this work, an adaptive oscillator-based assistive torque control was developed and implemented on a unilateral hip exoskeleton driven by a novel nonlinear series elastic actuator (nSEA), aiming at correcting gait asymmetry at hip joints during the whole gait cycle.

Fully Automatic Dual-Probe Lung Ultrasound Scanning Robot for Screening Triage.

Two-dimensional lung ultrasound (LUS) has widely emerged as a rapid and noninvasive imaging tool for the detection and diagnosis of coronavirus disease 2019 (COVID-19). However, image differences will be magnified due to changes in ultrasound (US) imaging experience, such as US probe attitude control and force control, which will directly affect the diagnosis results. In addition, the risk of virus transmission between sonographer and patients is increased due to frequent physical contact.

A Supervised-Reinforced Successive Training Framework for a Fuzzy Inference System and Its Application in Robotic Odor Source Searching.

Fuzzy inference systems have been widely applied in robotic control. Previous studies proposed various methods to tune the fuzzy rules and the parameters of the membership functions (MFs). Training the systems with only supervised learning requires a large amount of input-output data, and the performance of the trained system is confined by that of the target system.

Design of asymmetric-adhesion lignin-reinforced hydrogels based on disulfide bond crosslinking for strain sensing application.

Soft and elastic polymer hydrogel materials are booming in the fields of wearable biomimetic skin, sensors, robotics, and bioelectrodes. Currently, many researchers are exploring new chemistries for the preparation of hydrogels to improve their performance. In the present study, we design and develop a strategy to prepare lignin reinforced hydrogels based on disulfide bond crosslinking mechanisms, and resultant hydrogels exhibit excellent stretchability, with tensile strain of up to 1085.

Unsupervised Sim-to-Real Adaptation for Environmental Recognition in Assistive Walking.

Powered lower-limb prostheses with vision sensors are expected to restore amputees' mobility in various environments with supervised learning-based environmental recognition. Due to the sim-to-real gap, such as real-world unstructured terrains and the perspective and performance limitations of vision sensor, simulated data cannot meet the requirement for supervised learning. To mitigate this gap, this paper presents an unsupervised sim-to-real adaptation method to accurately classify five common real-world (level ground, stair ascent, stair descent, ramp ascent and ramp descent) and assist amputee's terrain-adaptive locomotion.

Preparation of Hemicellulose Nanoparticle-Containing Ionic Hydrogels with High Strength, Self-Healing, and UV Resistance and Their Applications as Strain Sensors and Asymmetric Pressure Sensors.

Smart functional fillers can significantly enhance the comprehensive properties of ionic hydrogels, such as their mechanical properties, which are key features of hydrogels in wearable sensor applications. As a plant-derived natural polymer, hemicellulose can serve as smart functional fillers. In this study, tannic acid-modified hemicellulose nanoparticles (TA@HC) and Fe were used in the preparation of PAA/TA@HC/Fe hydrogels.

Gait Phase Subdivision and Leg Stiffness Estimation During Stair Climbing.

Leg stiffness is considered a prevalent parameter used in data analysis of leg locomotion during different gaits, such as walking, running, and hopping. Quantification of the change in support leg stiffness during stair ascent and descent will enhance our understanding of complex stair climbing gait dynamics. The purpose of this study is to investigate a methodology to estimate leg stiffness during stair climbing and subdivide the stair climbing gait cycle.

Preparation and Performance of Lignin-Based Multifunctional Superhydrophobic Coating.

Superhydrophobic coatings have drawn much attention in recent years for their widespread potential applications. However, there are challenges to find a simple and cost-effective approach to prepare superhydrophobic materials and coatings using natural polymer. Herein, we prepared a kraft lignin-based superhydrophobic powder via modifying kraft lignin through 1H, 1H, 2H, 2H-perfluorodecyl-triethoxysilane (PFDTES) substitution reaction, and constructed superhydrophobic coatings by direct spraying the suspended PFDTES-Lignin powder on different substrates, including glass, wood, metal and paper.

Lignin reinforced hydrogels with fast self-recovery, multi-functionalities via calcium ion bridging for flexible smart sensing applications.

Hydrogels have found applications in many different fields. However, poor mechanical properties, such as low elasticity and lack of rapid recovery under large deformation, can severely limit their applications. In this study, we developed lignin reinforced hydrogels made of calcium ion containing ternary polymers (lignosulfonate (LS), alginate (Alg), and polyacrylic acid (PAA)).

Design of asymmetric-adhesion lignin reinforced hydrogels with anti-interference for strain sensing and moist air induced electricity generator.

Flexible hydrogels with integration of excellent mechanical and electrical properties are well suited for applications as wearable electronic sensors, and others. Self-adhesion is an important feature of wearable sensors. However, the usual isotropic- adhesion hydrogels have the drawback of poor anti-interference, which negatively affects their applications.

A Probability Distribution Model-Based Approach for Foot Placement Prediction in the Early Swing Phase With a Wearable IMU Sensor.

Predicting the next foot placement of humans during walking can help improve compliant interactions between humans and walking aid robots. Previous studies have focused on foot placement estimation with wearable inertial sensors after heel-strike, but few have predicted foot placements in advance during the early swing phase. In this study, a Bayesian inference-based foot placement prediction approach was proposed.

Preliminary Assessment of a Postural Synergy-Based Exoskeleton for Post-Stroke Upper Limb Rehabilitation.

Upper limb exoskeletons have drawn significant attention in neurorehabilitation because of the anthropomorphic mechanical structure analogous to human anatomy. Whereas, the training movements are typically unorganized because most exoskeletons ignore the natural movement characteristic of human upper limbs, particularly inter-joint postural synergy. This paper introduces a newly developed exoskeleton (Armule) for upper limb rehabilitation with a postural synergy design concept, which can reproduce activities of daily living (ADL) motion with the characteristics of human natural movements.

Understanding and Calibration of Charge Storage Mechanism in Cyclic Voltammetry Curves.

Noticeable pseudo-capacitance behavior out of charge storage mechanism (CSM) has attracted intensive studies because it can provide both high energy density and large output power. Although cyclic voltammetry is recognized as the feasible electrochemical technique to determine it quantitatively in the previous works, the results are inferior due to uncertainty in the definitions and application conditions. Herein, three successive treatments, including de-polarization, de-residual and de-background, as well as a non-linear fitting algorithm are employed for the first time to calibrate the different CSM contribution of three typical cathode materials, LiFePO , LiMn O and Na Fe (PO ) P O , and achieve well-separated physical capacitance, pseudo-capacitance and diffusive contributions to the total capacity.

Allowing the Load to Swing Reduces the Mechanical Energy of the Stance Leg and Improves the Lateral Stability of Human Walking.

Loaded walking with typical rigid backpack results in a significant increase in the mechanical energy of the stance leg and a decrease in lateral stability. Allowing the load to swing, which has been applied in shoulder pole, a tool widely used in Asia for load carriage assistance, may attenuate these effects. This paper theoretically analyzes and experimentally validates the biomechanical and energetic effects of the swinging loads.

A model to predict ground reaction force for elastically-suspended backpacks.

Background: Leg muscle fatigue is the most important factor that affects walking endurance. Considering the legs act as actuators in alternate contact with the ground during walking, the ground reaction force (GRF) of each leg can indirectly reflect the strength of leg muscles. However, it is not clear how the elastically-suspended backpack (ESB) affects GRF of each leg during human level walking.