Research Summary

My research is highly multi-disciplinary at the crossroad between Mechanics, Soft Materials, Robotics, and Bioengineering. Not surprisingly, my research contributions present across a wide range of fields. 

​At the intersection of these four fields, my research focuses on better interfacing  between human and machines enabled by advanced soft materials technologies. Human body and machines can form various types of interfaces including mechanical and electrical interfaces. To address existing grand challenges at these interfaces, I have explored a wide range of topics including Robust Wet Adhesion, Hydrogel Bioelectronics, Soft Active Materials and Robots, and 3D Printing of Soft Materials.

Research Interests

Note: Related first authored papers are referred with links

Robust Wet Adhesion

Human body is made out of a wide range of hydrogel-like soft and wet materials. Unlike conventional engineering materials such as metals, ceramics, plastics, and rubbers, soft wet human body and hydrogels pose significant challenges in terms of robust and reliable integration. In order to address this grand challenge, I have proposed and developed tough bonding of hydrogels (Nature Materials, 2016) and robust hydrogel-elastomer hybrids (Nature Communications, 2016). With these fundamental developments, I have explored various types of applications including wearable living devices (PNAS, 2017) and hydrogel skin for biomedical device (Advanced Materials, 2019). More recently, I have expanded our capability of robust wet adhesion to biological tissues (​Nature, 2019) and conducting polymer hydrogels (Science Advances, 2019).

Hydrogel Bioelectronics

Bioelectronic interfacing is one of the most important ways to interchange information between human body and artificial systems, mostly in the form of electronic devices. However, stark differences between two different realms demand a better bridging interface. In order to offer an improved bioelectronic interfacing between human body and artificial systems, I have proposed the concept of stretchable hydrogel electronics devices (Advanced Materials, 2016) as well as a comprehensive review on hydrogel bioelectronics (Chemical Society Reviews, 2018). With these fundamental understandings, I have developed a set of next generation materials and devices for hydrogel bioelectronics including pure PEDOT:PSS hydrogels (Nature Communications, 2019) and hydrogel hybrid neural probes (Nature Communications, 2019).

3D Printing of Soft Materials

3D printing is a versatile fabrication tactic for a wide range of soft materials. 3D printing of soft materials has rapidly growing importance and interesting research perspectives including materials, mechanics, and various applications. I have proposed and developed a diverse aspects of 3D soft materials printing including mechanics of 3D printing (Advanced Materials, 2017), 3D printing of living responsive devices (Advanced Materials, 2017), ferromagnetic 3D printing of programmable soft active materials (Nature, 2018), and 3D printing of high-performance PEDOT:PSS (Nature Communications, 2019).

Soft Active Materials and Robots

Soft and flexible motions of various creatures in nature provide great inspiration for unconventional soft and flexible machines and robots. I have proposed and developed diverse kinds of soft active materials and robots including shape memory alloy-based robot mimicking C. elegance (Bioinspiration & Biomimetics, 2011), transparent hydraulic hydrogel robots (Nature Communications​, 2017), and magnetically actuated soft materials with programmed ferromagnetic domains (Nature, 2018).