Publications by authors named "Joonbum Bae"

Article Synopsis
  • Soft robotic grippers are improving in contact reliability but still can't match human grasping skills; this study introduces a sensorized multi-fingered gripper with bioinspired adhesive tips.
  • The gripper’s adhesive fingers feature mushroom-shaped microstructures for better grip, allowing it to support substantial loads (4.18 N per fingertip and 28.29 N for three fingers).
  • Its design includes independently actuated joints and a kirigami-patterned sensor for movement tracking, demonstrating effective handling of various objects and even use in remote-controlled cooking.
View Article and Find Full Text PDF
Article Synopsis
  • - The article discusses the rise of origami in fields like architecture and robotics, emphasizing its unique ability to transform flat sheets into complex shapes, although origami robots struggle with rigidity in demanding environments.
  • - It introduces self-locking pneumatic modular actuators (SPMAs) inspired by origami, which can achieve various shape movements and improved stiffness by embedding magnets in composite materials.
  • - The design includes self-adjustable valves that streamline control for multiple actuators using a single power source, enhancing the functionality of robotic systems, especially in tight spaces.
View Article and Find Full Text PDF

Soft inflatable robots are a promising paradigm for applications that benefit from their inherent safety and adaptability. However, for perception, complex connections of rigid electronics both in hardware and software remain the mainstay. Although recent efforts have created soft analogs of individual rigid components, the integration of sensing and control systems is challenging to achieve without compromising the complete softness, form factor, or capabilities.

View Article and Find Full Text PDF

As the wearable heater is increasingly popular due to its versatile applications, there is a growing need to improve the tensile stability of the wearable heater. However, maintaining the stability and precise control of heating in resistive heaters for wearable electronics remains challenging due to multiaxial dynamic deformation with human motion. Here, we propose a pattern study for a circuit control system without complex structure or deep learning of the liquid metal (LM)-based wearable heater.

View Article and Find Full Text PDF
Article Synopsis
  • Certain aquatic insects use surfactants to move quickly on water, which has inspired research into self-propelling robots.
  • This study presents a new method for liquid fuel delivery using a microfluidic pump that autonomously transports fuel to enable Marangoni propulsion.
  • By analyzing different design parameters, researchers found ways to control the robot's movement distance, energy usage, and direction, potentially advancing the development of self-propulsion systems.
View Article and Find Full Text PDF
Article Synopsis
  • Variable stiffness in soft robotics is crucial for effective manipulation, traditionally achieved through jamming mechanisms but often limited in force capacity.
  • The article presents a novel hybrid jamming structure that combines granules and rigid chains to enhance stiffness and force capabilities in various directions.
  • Experimental validation and design principles for this hybrid structure were established, leading to the development of a multilink system aimed at enhancing upper limb mobility in wearable applications.
View Article and Find Full Text PDF

Soft robots have been extensively researched due to their flexible, deformable, and adaptive characteristics. However, compared to rigid robots, soft robots have issues in modeling, calibration, and control in that the innate characteristics of the soft materials can cause complex behaviors due to non-linearity and hysteresis. To overcome these limitations, recent studies have applied various approaches based on machine learning.

View Article and Find Full Text PDF
Article Synopsis
  • Various wearable systems for measuring hand motion face challenges, including the need for calibration to convert sensor signals to actual finger joint angles.
  • This paper introduces an exoskeleton system utilizing linear Hall sensors to measure hand motion in three dimensions without requiring calibration, thanks to absolute rotation measurement.
  • The proposal includes a new fitting method to accommodate different hand sizes and a unique approach to measure the thumb's CMC joint to accurately determine its orientation, with experimental validation using an optical motion capture system.
View Article and Find Full Text PDF

In this study, finger force control abilities are quantified by the concept of multi-finger synergy in conjunction with uncontrolled manifold (UCM) analysis. Two indices, named repeatability and flexibility, representing features of multi-finger synergy were proposed to overcome the limitation of previously introduced indices, such as floor effects and distortion problems. The proposed indices were applied to stroke patients and healthy adults through specifically designed experiments.

View Article and Find Full Text PDF

Drag-based swimming is usually accompanied with the shape change of rowing appendages to generate asymmetric force during the power stroke and recovery stroke. To implement this in an aquatic robot, one may actively control the surface area of its legs during the swimming. However, a small sized robot with a limited number of actuators should adjust the surface area of legs in passive manner.

View Article and Find Full Text PDF
Article Synopsis
  • * These indices were tested on stroke patients and healthy adults using specially designed experiments, revealing significant differences in finger force control between the two groups.
  • * Additionally, results indicated varying outcomes within stroke patients based on whether their dominant or non-dominant hand was affected.
View Article and Find Full Text PDF
Article Synopsis
  • A new technique was developed to improve the electrical connections in liquid metal-based stretchable electronics by directly writing conductive liquid metal paths on silicone substrates.
  • The study found that using electroless nickel immersion gold (ENIG) finished metal electrodes resulted in stable connections with low contact resistance.
  • The method allows for the creation of soft sensor systems that can measure joint angles and forces, utilizing only readily available materials, making the design of flexible electronics simpler and more efficient.
View Article and Find Full Text PDF
Article Synopsis
  • Many studies have focused on using eutectic gallium-indium as a conductive ink for creating stretchable sensors, but traditional mold-based methods suffer from inconsistent results due to manual fabrication.
  • This study utilized direct ink writing to enhance the stability and reproducibility of sensor manufacturing by optimizing process variables like syringe material.
  • The new technique not only improved the accuracy of creating microchannels but also allowed for the development of a seamless glove-type sensor, streamlining the fabrication process.
View Article and Find Full Text PDF
Article Synopsis
  • The article discusses the development of bio-inspired robots by studying animal locomotion, particularly focusing on aquatic arthropods.
  • While there's considerable research on either animals or their robotic counterparts, there's a lack of comprehensive reviews that connect both fields.
  • It highlights that despite existing studies, many aspects of aquatic locomotion in these animals remain under-explored, suggesting new research opportunities for creating more agile and efficient aquatic robots.
View Article and Find Full Text PDF
Article Synopsis
  • The paper presents a wearable hand exoskeleton designed to assist in the flexion and extension of fingers, operating with a single degree of freedom (DOF).
  • Experiments with physically capable individuals were conducted to understand typical hand movements, resulting in a polynomial curve that represents these motions.
  • The exoskeleton's design was customized to fit individual users by adjusting the polynomial curve to their joint range of motion and was built as a lightweight prototype using just two linear motors to power separate parts for the thumb and other fingers.
View Article and Find Full Text PDF

To investigate, improve, and observe the effect of rehabilitation therapy, many studies have been conducted on evaluating the motor function quantitatively by developing various types of robotic systems. Even though the robotic systems have been developed, functional evaluation of the hand has been rarely investigated, because it is difficult to install a number of actuators or sensors to the hand due to limited space around the fingers. Therefore, in this study, a hand exoskeleton was developed to satisfy the required specifications for evaluating the hand functions including spasticity of finger flexors, finger independence, and multi-digit synergy and algorithms to evaluate such functions were proposed.

View Article and Find Full Text PDF

The locomotion of water beetles has been widely studied in biology owing to their remarkable swimming skills. Inspired by the oar-like legs of water beetles, designing a robot that swims under the principle of drag-powered propulsion can lead to highly agile mobility. But its motion can easily be discontinuous and jerky due to backward motions (i.

View Article and Find Full Text PDF
Article Synopsis
  • The study introduces a new motion measurement system using soft sensors made of Ecoflex with embedded channels of conductive liquid metal for better finger movement tracking.
  • These soft sensors are lightweight, flexible, and sensitive, allowing them to be used in challenging environments where traditional sensors fail.
  • The effectiveness of the system and its algorithms for measuring finger joint angles is validated against a conventional camera-based motion capture system.
View Article and Find Full Text PDF
Article Synopsis
  • Conventional gait rehabilitation often lacks quantitative insights into abnormal movement patterns and can be limited by the clinician's expertise.
  • The paper introduces a mobile gait monitoring system (MGMS) that includes Smart Shoes and a processor to track patients' gait by analyzing ground reaction forces (GRFs) in real-time.
  • This system allows patients to receive visual feedback on their gait, enabling them to practice rehabilitation anytime and anywhere, improving their chances for effective recovery.
View Article and Find Full Text PDF