Since hydrogel can provide a mass-permeable and ultra-soft interface, our group developed the functionality of hydrogel and hydrogel-based stretchable bioelectronics to present a tissue-like material system. Engineering hydrogel-forming mechanism is important to determine therapeutic application. With in-situ polymerization and degrading nature, we presented injectable hydrogel drug-delivery systems with nanotherapeutics (^(ⅰ)ACS Nano, 2022; ^(ⅱ)ACS Nano, 2023). Further, highly conductive and adhesive hydrogel was introduced with nanomaterial engineering (^(ⅲ)Advanced Materials, 2024) enabling efficient electroceutical demonstration. We are advancing research in processing techniques that enable precise patterning and integration of soft materials, which is crucial for optimizing the composition and properties of the devices(^(ⅳ)Science Advances, 2021; ^(M)Science Advances, 2024). Such integration enhances device functionality, allowing for unrestricted movement and real-time health data monitoring through advanced sensor capabilities. The innovative technologies hold vast potential for applications in rehabilitation, long-term monitoring, and disease prevention and management, underscoring the importance of our cutting-edge research in this field.

Electronic skin(E-skin) and wearable device technology is advancing rapidly with applications in healthcare, prosthetics, and robotics. Our research focuses on developing wearable sensing, signal processing, and data storage devices (^(ⅰ)Science Advances, 2017; ^(ⅱ)Science Advances, 2016) by designing and fabricating stretchable materials and devices to ensure high reliability, performance, and stable operation during dynamic movement ((^(ⅲ)Nature Nanotechnology, 2014; ^(ⅳ)Nature Electronics, 2023). We also enhance the multimodal sensing capabilities of E-skin, enabling simultaneous detection of pressure, temperature, glucose, pH, and humidity, while seamlessly integrating sensing, feed back therapy, and signal processing functions (^(M)Nature Communications, 2014; ^(ⅴ)Nature Nanotechnology, 2016). Looking ahead, we aim to push the boundaries of E-skin technology by incorporating machine learning, expanding its applications in advanced robotic hands, human-machine interface, and cutting-edge biomedical systems (ref 3).

Soft hardware is a crucial element in advancing digital healthcare by minimize the mechanical mismatch between biological tissues and artificial systems. To implement such electronic systems, we focus on designing appropriate form factors for long-term and seamless integration with the human body. In scenarios requiring continuous monitoring, direct intervention, or immediate therapeutic efficacy from various diseases and environmental factors, user-friendly wearable and/or implantable devices are essential. Beyond providing bioelectronic interfaces, we aim to apply practical and reliable minimally invasive and/or wireless strategies to the system for everyday life, aiming to advance digital healthcare systems. To achieve such a mission, we developed wireless smart cell culture platform (^(ⅰ)Nature Communications, 2019) and minimally invasive surgical tools (^(ⅱ)Nature Communications, 2015; ^(ⅲ)Advanced Materials, 2024), researched wireless drug delivery strategy using biodegradable soft materials (^(ⅳ)Nature Communications, 2019), and created locally drug delivering microneedles (^(ⅴ)Advanced Materials, 2021). Additionally, we developed wirelessly integrated implantable and wearable platforms (^(M)Science Advances, 2021) and a robust wireless power transfer strategy for implantable device (^(ⅵ)Science Advances, 2022). Our mission will continue to create human-friendly soft bioelectronics.

Focusing on the development of Quantum Dot-based flexible and stretchable displays, our research group is dedicated to pioneering advancements in display technology. We have proposed a high-efficiency full color QLED arrays (^(ⅰ)Nature Communications, 2015) as well as electronic tattoo applications using high-resolution intaglio transfer printing method. We have also developed ultrathin skin-attachable QLED display (^(ⅱ)Advanced Materials, 2017) that can visualize various types of information retrieved from the wearable electronics, in close proximity to the wearer’s skin. Furthermore, we have demonstrated highly bright and transparent QD-LEDs (^(ⅲ)Advanced Materials, 2017) with an ultrathin form factor and high color purity. We have reported the design and fabrication of 3D foldable QLEDs (^(ⅳ)Nature Electronics, 2021). Through controlled folding method, we have created customized 3D architectures of foldable QLEDs. Recently, we have reported intrinsically stretchable QLEDs (^(M)Nature Electronics, 2024) that can stretch up to 50% without significant brightness loss by developing a stretchable quantum-dot based ternary nanocomposite. This technology hold immense potential for various stretchable display applications.

Bio-inspired artificial vision draws inspiration from the remarkable capabilities of natural vision systems. A key advantage of bio-inspired artificial vision is its potential to handle challenging conditions in image acquisition and processing that traditional vision systems may struggle with. Natural vision systems have evolved over millions of years to operate effectively in diverse environments, including low-light conditions, dynamic scenes, and cluttered surroundings. By leveraging the strategies employed by natural vision systems, artificial vision systems can become more adaptable and resilient in future mobile electronics, including humanoids, self-driving vehicles and multifunctional probes. We have developed unique artificial imaging systems inspired by various natural vision system, including humans (^(ⅰ)Nature Communications, 2017; ^(ⅱ)Nature Nanotechnology, 2022), aquatic animals(^(ⅲ)Nature Electronics, 2020; ^(ⅳ)Science Robotics, 2023; ^(M)Nature Electronics, 2022), birds(^(ⅴ)Science Robotics, 2024), and terrestrial animals(^(ⅵ)Nature Communications, 2024; ^(ⅶ)Science Advances, 2024) as well as inspired by human brain neural networks for in-sensor computing (^(ⅷ)Nature Communications, 2020; ^(ⅸ)Science Advances, 2022). Further, the development of novel 2D material synthesis methods (^(ⅹ) Nature Synthesis) boost up the performance of bio-inspired artificial vision systems.

We developed floatable photocatalytic hydrogel nanocomposites (^(M)Nature Nanotechnology, 2023) and nitrogen-fixing microbial biocomposites (^(ⅰ)Advanced Materials, 2023) for efficient and sustainable solar hydrogen production and compact device integrating photo- and electrocatalysis for closed-loop fuel production (^(ⅱ)Device, 2024). We are expanding our research focus towards plastic waste upcycling, machine learning-aided bio-hybrid optimization, H₂O₂ production via ORR, organic high C# fuel synthesis, and maximizing utilization of solar thermal energy.

Our research on unconventional energy devices focuses on wearable and human-friendly energy solutions. We have developed stretchable energy harvesting systems and wearable energy storage devices(^(ⅰ)Advanced Functional Materials, 2017) as well as biocompatible and biodegradable batteries(^(ⅱ)Advanced Materials, 2021), designed to power wearable and human-friendly electronic systems. High-quality flexible thin-film battery can be fabricated through the damage-free dry transfer method(^(M)Nature Materials, 2024), enhancing the portability and usability of the bio-integrated electronic systems. We also developed transparent photovoltic devices and colored solar windows for sustainable and distributed solar power generation (^(ⅲ)Nature Communications, 2022), based on our perovskite patterning method (^(ⅳ)Advanced Materials, 2017). These technologies represent a step forward in energy device technologies for sustainable future.