김선정 교수

Highly elastic and electrically conductive composite sheets are prepared by infiltration of MWNT forests with polyurethane binder. After initial pretreatment, the composite provides highly reproducible changes in resistivity at elongations up to 40%. Almost no degradation in electrical properties and a linear dependence of resistivity on strain is observed for strains in 10%–20% range.

The fabrication and characterization of highly flexible textiles are reported. These textiles can harvest thermal energy from temperature gradients in the desirable through-thickness direction. The tiger yarns containing n- and p-type segments are woven to provide textiles containing n-p junctions. A high power output of up to 8.6 W m(-2) is obtained for a temperature difference of 200 °C.

Ferritin-based nanofibrous hydrogels that demonstrate synergy between the ferritin protein and the synthetic polymer matrix are fabricated. The hybrid hydrogels showed enhanced mechanical properties and repeated expansion and contraction without showing severe creep during pH switching. The ferritin nanoparticles incorporated into the hydrogel nanofibers improved the actuation stability of a hydrogel actuator by acting as elastic nanosprings in a nanoscale polymer.

While artificial muscle yarns and fibers are potentially important for many applications, the combination of large strokes, high gravimetric work capacities, short cycle times, and high efficiencies are not realized for these fibers. This paper demonstrates here electrochemically powered carbon nanotube yarn muscles that provide tensile contraction as high as 16.5%, which is 12.7 times higher than previously obtained. These electrochemical muscles can deliver a contractile energy conversion effi

Macroscopically coiled and microscopically buckled fiber electrodes are introduced for an ultra-stretchable supercapacitor. The pseudocapacitive MnO2-coated, solid-state, buckled coil supercapacitor provides superelasticity (400%–800%) and high linear, areal capacitances (4.8 mF cm−1 and 22.8 mF cm−2). Additionally, the capacitances of the supercapacitor decrease by less than 7.4% and 7% when stretched by 600% statically and dynamically, respectively. As a service to our authors and readers, thi

The flexible piezoelectric fibers can be stretched to a tensile strain of 5% and can generate over 50 μW·cm−3.The FPFs are sufficiently robust for knotting, sewing and weaving and can also be converting to piezoelectric coils by twist insertion. These spring-like coils can be reversibly stretched to 50% strain without failure.

Abstract An interpenetrating polymer network (IPN) hydrogel composed of poly(vinyl alcohol) (PVA) and chitosan exhibited electric‐sensitive behavior. The PVA/chitosan IPN hydrogel was synthesized by an ultraviolet (UV) irradiation method that is used in several biomedical and industrial fields. The swelling behavior of the PVA/chitosan IPN hydrogel was studied by immersion of the gel in NaCl aqueous solutions at various concentrations. The swelling ratio decreased with increasing concentration o

Hydrogels constructed from semi-interpenetrating polymer networks (semi-IPNs) of chitosan and polyaniline (CP) were prepared and the effect of various pH (1, 4, 7, 10) levels on the equilibrium water content (EWC) and electromechanical response were investigated. In swelling experiments, the freeze-dried membranes exhibited a high EWC value in acidic conditions. The electromechanical behavior of the CP membranes was also measured in a direct current electric field in pH buffer solutions. The ele