Science Advances
Accurate transmission of biosignals without interference of surrounding noises is a key factor for the realization of human-machine interfaces (HMIs). We propose frequency-selective acoustic and haptic sensors for dual-mode HMIs based on triboelectric sensors with hierarchical macrodome/micropore/nanoparticle structure of ferroelectric composites.
ACS Nano
The conductivity-gradient multilayers allowed us to control the saturation behavior of resistance change by the gradual activation of current pathway from outer to inner layers and the difference between initial and saturation resistances, thus ensuring the superior linearity and ultrahigh sensitivity (3.8 × 105 kPa−1 ) for the pressure range of up to 100 kPa.
ACS Nano
We developed high-performance TE devices through the structural design of ferroelectric multilayers with alternating PVDF-TrFE and BTO NP layers for enhanced polarization and stress concentration effects.
Science Advances
In this work, we presented an artificial tongue that is fully inspired from the human sensing mechanism. The artificial tongue can be prepared by facile UV polymerization on a flexible substrate and exhibit extraordinary sensing capabilities, such as a wide sensing range and a low limit of detectable concentration and high selectivity from other tastes.
Advanced Materials
This study demonstrates that a hierarchical NP-MP architecture in porous mechanochromic composites can enhance both mechanochromic strain/stress sensitivity and stretchability.
Science Advances
Nanomembranes and nanowires build tiny, transparent loudspeakers and sensitive, voice-recognition microphones that attach to skin.
Advanced Materials
Improved performance in plasmonic organic solar cells (OSCs) and organic light-emitting diodes (OLEDs) via strong plasmon-coupling effects generated by aligned silver nanowire (AgNW) transparent electrodes decorated with core–shell silver–silica nanoparticles ([email protected] 2 NPs) is demonstrated.
ACS Nano
Here, we demonstrate a flexible ferroelectric sensor with ultrahigh pressure sensitivity and linear response over an exceptionally broad pressure range based on the material and structural design of ferroelectric composites with a multilayer interlocked microdome geometry.
ACS Nano
Flexible, transparent, and force-sensitive touch screens using cross-aligned AgNW electrodes integrated with mechanochromic spiropyran–polydimethylsiloxane composite film. Our force-sensitive touch screens enable the precise monitoring of dynamic writings, tracing and drawing of underneath pictures, and perception of handwriting patterns with locally different writing forces.
Advanced Materials
By mimicking muscle actuation to control cavity-pressure-induced adhesion of octopus suckers, smart adhesive pads are developed in which the thermoresponsive actuation of a hydrogel layer on elastomeric microcavity pads enables excellent switchable adhesion in response to a thermal stimulus (maximum adhesive strength: 94 kPa, adhesion switching ratio: ≈293 for temperature change between 22 and 61 °C).

Functional Nanomaterials and Devices

Our research interests are centered on the development of functional nanomaterials and devices based on the micro- and nanostructures. We are interested in exploiting the fabrication strategies combining “bottom-up” assembly and “top-down” lithography to hierarchically organize organic and inorganic nanomaterials (carbon nanotubes, graphenes, nanowires, nanoparticles, …) on multiple length scales. We also seek to understand the fundamental physical properties of individual nanomaterials and the collective behavior of the organized micro- and nanostructures, which is central to the rational development of functional devices. Ultimately, these micro- and nanostructures may find use in electronics, optics, sensors, and biomedical devices.
Ko lab

News & Achievement

Congratulations for winning the best poster award in MRS2022SpringMeeting

Posted on 16 May 2022
Jinyoung Kim won the best poster award in MRS2022 Spring Meeting, Hawaii.

Congratulations for winning a NRF Fellowship

Posted on 16 May 2022
Sangyun Na won a NRF Fellowship (이공계열 학문후속세대 장학금).

Congratulations for winning the best poster award at MRS2022SpringMeeting

Posted on 16 May 2022
Jeonghee Yeom won the best poster award in MRS2022 Spring Meeting, Hawaii.  

Congratulations for winning the best poster presentation award at The Polymer Society of Korea

Posted on 13 Apr 2022
Hyejin Lee won the best poster presentation award in The Polymer Society of Korea, Apr 2022.

Congratulations for winning the best poster presentation award at The Polymer Society of Korea

Posted on 09 Apr 2022
Dong-hee Kang won the best poster presentation award in The Polymer Society of Korea, Apr 2022.

Recent Publications

Journal publication : ACS Nano

Posted on 28 Jul 2022
Sujoy Kumar Ghosh, Jinyoung Kim, Minsoo P. Kim, Sangyun Na, Jeonghoon Cho, Jae Joon Kim, and Hyunhyu

Journal publication : Polymer Chemistry

Posted on 11 Jul 2022
Pothanagandhi Nellepalli, Twinkal Patel, Minsoo P. Kim, Junyoung Park, Zhibin Ye, Hyun Wook Jung*, H

Journal publication : Nano Energy

Posted on 08 Jun 2022
 Sujoy Kumar Ghosh, Minsoo P. Kim, Sangyun Na, Youngsu Lee, Jonghwa Park, Seungse Cho, Jeonghoon Cho

Journal publication : Science Advances

Posted on 26 Mar 2022
Jonghwa Park, Dong-hee Kang, Heeyoung Chae, Sujoy Kumar Ghosh, Changyoon Jeong, Yoojeong Park, Seung

Journal publication : Advanced Science

Posted on 15 Mar 2022
Young-Eun Shin, Yong-Jin Park, Sujoy Kumar Ghosh, Youngoh Lee, Jonghwa Park, and Hyunhyub Ko* “Ultra

Position available

There are several openings for graduate students and researchers in the area of functional nanomaterials and devices. Feel free to contact Prof. Ko (e-mail: [email protected], tel: 052-217-2532) if you are interested.