Our foundational research focuses on designing hydrogel networks that combine extraordinary mechanical deformability with tunable ionic conductivity. By engineering double-network architectures — pairing covalently crosslinked backbones with physically associating ionic or hydrophobic domains — we achieve hydrogels that can sustain strains exceeding 1000% while maintaining structural integrity.
We investigate the role of zwitterionic monomers, ionic crosslinkers, and hygroscopic salts in modulating network mesh size, water content, and charge carrier mobility. The resulting structure–property relationships guide the design of ionogels and hydrogels suited for use as electrolytes, electrodes, and encapsulants in soft electronic systems.
Translating material properties into functional device geometries requires precise fabrication strategies. We develop and adapt 3D printing and microfluidic spinning techniques to produce hydrogels and ionogels with well-defined shapes — from continuous fibers and core–shell capsules to multilayer thin films and freestanding membranes.
Our microfluidic platform enables the continuous formation of hydrogel optical fibers with sub-millimeter diameters, where the fiber geometry, wall thickness, and core composition are independently controlled by adjusting flow rates and channel geometry. 3D printing allows spatial patterning of stiffness, conductivity, and optical properties within a single printed construct.
A key challenge in soft electronics is creating electrode materials that remain conductive under large mechanical deformation. We design intrinsically stretchable conductors based on ionic hydrogels and ionogels, where conductivity arises from mobile ions rather than rigid metallic pathways. These materials are transparent, biocompatible, and compatible with skin-conformal device integration.
Post-growth engineering strategies — such as in-situ deposition of metal nanowire networks or carbon nanotube coatings onto pre-formed hydrogel substrates — allow us to introduce electronic conductivity without sacrificing stretchability. The resulting composite electrodes serve as active components in supercapacitors, electroluminescent devices, and electrophysiological sensors.
Wearable electronics require power sources that can flex, stretch, and conform to the body without performance degradation. We develop two classes of deformable energy devices: triboelectric nanogenerators (TENGs) that harvest mechanical energy from body motion, and microsupercapacitors that store the harvested energy for on-demand use.
Our TENG designs combine high-dielectric-constant elastomeric films with double-network hydrogel electrodes, achieving high output voltage under repeated deformation. The microsupercapacitor work introduces a nanoneedle bridging mechanism — wherein metal nanoneedles grown on fiber electrodes bridge across the electrode–electrolyte interface to dramatically reduce contact resistance while preserving full intrinsic stretchability.
Electroluminescent (EL) devices based on ionic hydrogel electrodes can sustain brightness over strains exceeding 1400% — a regime inaccessible to conventional ITO-based devices. We exploit this capability to develop soft displays and wearable indicators that deform with the body while maintaining visible light emission.
Our recent work introduces quantum-dot-based color converters patterned directly onto EL device surfaces, enabling full-color emission from a single AC-driven device. 3D printing is used to deposit multilayer dielectric and emissive stacks with spatial color patterning, opening new possibilities for stretchable multicolor displays and bio-integrated light sources.
The materials and fabrication strategies developed in our lab converge in the design of devices that interface with living systems. Skin-adhesive hydrogel patches are used for continuous electrophysiological monitoring, where the gel's softness and adhesion ensure conformal skin contact without irritation. Pressure sensors based on piezoresistive hydrogel composites enable wearable gait and posture monitoring.
Hydrogel optical fibers serve as dual-function light guides and ion conductors for photobiomodulation therapy, where near-infrared light is delivered to tissue through the transparent fiber body. Collaboration with biomedical researchers (Czech Academy of Sciences; Korea-Czech bilateral program) extends these materials toward in vitro cell stimulation and implantable scaffold applications.