Projects
Fully 3D printable robot hand with soft tactile sensor
May 2023 - March 2024, at KIMLAB, University of Illinois Urbana-Champaign (with Interactive Robot Lab, DGIST)
Fully 3D printable robot hand equipped with soft tactile sensors are developed.
The developed robotic hand consists solely of 3D printed parts and commercial motors, with a total cost of less than $400.
The tactile sensors are based on pneumatic and capacitive sensors and are capable of detecting not only sensitive forces but also the presence of nearby conductive objects.
MOMO: Mobile Object Manipulation Operator
April 2023 - September 2023, at KIMLAB, University of Illinois Urbana-Champaign
KIMLAB demonstrated the mobile object manipulation operator (MOMO) at IROS 2023, Detroit, US.
This demonstration showcased an innovative modular mobile manipulator system, incorporating three pluggable mounts that can utilize 6-DOF arms and a sensor module for different configurations, thereby enhancing the system’s capabilities beyond those of a traditional serving robot.
The primary objectives of the system encompass the autonomous removal of obstructions from the floor and seamless delivery to human recipients without any human intervention.
Low-cost and easy-to-build soft pneumatic robotic skin for safe and contact-rich pHRI
April 2022 - September 2023, at KIMLAB, University of Illinois Urbana-Champaign
Soft pneumatic robotic skin is developed for plug-and-playable robotic arm system (PAPRAS) by KIMLAB. The developed robotic skin was seamlessly integrated with the robot from both hardware and software pespectives.
The developed soft sensing pad is cheap and easy to produce as it is entirely 3D printable. Also, the sensing electronics are design to be compatible with ROS, making the system highly accessible to everyone.
Soft pad's internal pressure changes due to tactile stimuli such as force and light touch. The measured signals are divided into low and high frequencies and were utilized for interaction or communication.
The developed system was demonstrated to be capable of effectively handling situations such as joint entrapment and multiple contacts, thereby realizing safe and contact-rich pHRI.
A biomimetic elastomeric robot skin using electrical impedance and acoustic tomography for tactile sensing
March 2021 - June 2022, at KAIST (with MIT and Univ. of Stuttgart)
Skin-inspired multi-layer structure is fabricated using silicone elastomer and ionic hydrogel, which show squish yet durable properties.
The ionic hydrogel layer is used as a medium for tactile sensing since it can transmit alternating electric currents and vibrations.
The tomographic imaging methods are utilized to reconstruct a multi-modal tactile image from measurement data.
A convolutional neural network allows the robotic skin to classify the type of touch by extracting the spatio-temporal pattern of the tactile stimuli.
The developed robotic skin can be repaired using chitosan topohesive and silicone adhesive, even after severe damage (incision).
The sensorized prosthesis was implemented as a proof-of-concept
Neural-gas network-based optimal design method for ERT-based whole-body robotic skin
December 2019 - November 2021, at KAIST
We developed a method to obtain an optimal electrode arrangement for ERT-based robotic skin.
The electrode arrangement is iteratively updated to maximize the minimum current density of the ERT-based robotic skin.
Each electrode spreads out like a gas molecule inside the sensing domain, forming a grid-like arrangement adapted to the sensor's geometry.
A number of electrodes can be freely adjusted to meet design requirements, owing to the automated design process.
We implemented an ERT-based robotic skin with optimal design, and demonstrated physical human-robot interaction (pHRI).
Adaptive and Optimal Measurement Algorithm for ERT-based Large-area Tactile Sensors
December 2019 - October 2020, at KAIST
The performance of ERT-based sensors is improved by increasing the number of electrodes, but the number of measurements and the computational cost also increase.
We propose an adaptive and optimal measurement algorithm for ERT-based tactile sensors; the measurement pattern consists of a base pattern and local patterns.
The tactile events are detected by a base pattern that maximizes the distinguishability of local conductivity changes.
A set of local patterns are selectively recruited near the stimulated region to acquire more detailed information.
The algorithm was implemented with a field-programmable gate array (FPGA).
An ERT-based Robotic Skin using with Sparsely Disributed Electrodes: Structure, Fabrication, and DNN-based signal Processing
April 2019 - November 2019, at KAIST
We ERT-based tactile sensing on the cylindrical surface of the robot
The electrodes are evenly placed on the robot surface, and seamlessly integrated onto the robot surface
The CNT-based conductive surface formed by spray coating
The 3D shell-shape simulation model is used, and the deep neural network is utilized to compensate nonlinear behavior of the sensor
Whole-body Robotic Skin using Electrical Resistance Tomography (ERT) with Multiple Internal Electrodes
March 2018 - March 2019, at KAIST and Max Planck Institute for Intelligent System
We developed soft robotic skin based on Electrical resistance tomography.
It shows higher spatial resolution due to the multiple internal electrodes.
We utilized a conductive fabric-based transduction mechanism.
Soft Tactile Sensor using CNT-coated Porous PDMS and Interference Reduction Structure
March 2016 - February 2018, at KAIST
We developed a soft tactile sensor using a CNT-coated porous PDMS and an interference reduction structure
It shows low hysteresis due to the CNT-coated porous PDMS.
It shows low interference due to the interference reduction structure.
It can be customized to have a curved shape of the robotic body.
3D Robotic Skin using Tomographic Imaging and CNT-Polymer Mixture
July 2017 - December 2017, at KAIST
We developed robotic skin that can measure the tactile information on the hand and bending of the finger
The CNT-silicone rubber mixture is utilized as a piezoresistive material
Electrical Impedance Tomography (EIT) based scanning mechanism
Multi-axial Ground Reaction Force (GRF) Sensor
March 2015 - August 2015, at KAIST
A two-dimensional ground reaction force (GRF) measurement system is developed by using optical sensors
We reduce the interference by implementing an interference-free structure
We could measure and analyze the gait phase pattern of the human by attaching the sensor to shoes
The wearable system is capable of Bluetooth communication