A tungsten bronze structured ceramic material as a thermal barrier coating is described wherein the tungsten bronze structured ceramic coating material has the formula AO\u2014BvOw\u2014CyOz where O stands for Oxygen, A stands for a 2+ or a 1+ cation, B stands for a 2+ or 3+ cation and C stands for a 4+ or a 5+ cation. Similar methods of production of nanotubes are also disclosed. Each of the plurality of transistors has a first gate electrode which is input with a logic signal, a second gate electrode which is input with the Vth control signal, and a semiconductor film such that the second gate electrode, the semiconductor film, and the first gate electrode are provided in this order from the bottom. It is thus advantageously possible to detect or measure the forces acting on the band in a non-electric manner and, on the basis of this detection or measurement, draw conclusions relating to the widening or narrowing of the torso. The screens are rotatably attached to the body of the device in a manner that does not obscure the primary display screen, so that the user need not deploy them unless needed.