New structures with richer electromagnetic properties are in high demand for developing novel microwave and optic devices aimed at realizing fast light-based information transfer and information processing. Here we show theoretically that a topological photonic state exists in a hexagonal LC circuit with short-range textures in the inductance, which is induced by a band inversion between p- and d-like electromagnetic modes carrying orbital angular momentum, and realize this state experimentally in planar microstrip arrays. Measuring both amplitude and phase of the out-of-plane electric field accurately using microwave near-field techniques, we demonstrate directly that topological interfacial electromagnetic waves launched by a linearly polarized dipole source propagate in opposite directions according to the sign of the orbital angular momentum. The open planar structure adopted in the present approach leaves much room for including other elements useful for advanced information processing, such as electric/mechanical resonators, superconducting Josephson junctions and SQUIDs.

General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. Full terms of use are available: http://www.bristol.ac.uk/pure/about/ebr-terms

A light-responsive delivery system has been developed. It consists of gelly microspheres made of TEMPO-oxidized Konjac glucomannan (OKGM) polymers where the carboxyl (COO(-)) groups are cross-linked via ferric ions (Fe(3+)) and in which functional ingredients may be incorporated. By irradiation with (simulated) sunlight, the microspheres degrade, thereby releasing the encapsulated component(s). The degree of oxidation (DO) of the OKGM polymers could be well-controlled between 15 and 80%, as confirmed by proton titrations and FT-IR spectroscopy. OKGM of DO 80% was selected to prepare the microspheres because the high COO(-) content leads to a high density of cross-links, yielding a strong gel. The electrokinetic potential of the OKGM particles increases with increasing pH and decreasing salt concentration. Mössbauer and FT-IR spectroscopy revealed that the cross-links are formed through two modes of COO(-)-Fe(3+) coordination, that is, 68.4% by bridging and 31.6% by unidentate binding. Thus, the unique properties of the OKGM microspheres make them potentially applicable as light-controlled biocompatible delivery systems.

No abstract

No abstract