  The ability to design the control of heat flow has innumerable benefits in
the design of electronic systems such as thermoelectric energy harvesters,
solid-state lighting, and thermal imagers, where the thermal design plays a key
role in performance and device reliability. However, to realize one advanced
control function of thermal flux, one needs to design one sophisticated,
multilayered and inhomogeneous thermal structure with different
composition/shape at different regions of one device. In this work, we employ
one identical sensu-unit with facile natural composition to experimentally
realize a new class of thermal metamaterials for controlling thermal conduction
(e.g., thermal concentrator, focusing/resolving, uniform heating), only
resorting to positioning and locating the same unit element of sensu-shape
structure. The thermal metamaterial unit and the proper arrangement of multiple
identical units are capable of transferring, redistributing and managing
thermal energy in a versatile fashion. It is also shown that our sensu-shape
unit elements can be used in manipulating dc currents without any change in the
layout for the thermal counterpart. The proposed scheme can also be applied to
control dc electric currents and dc magnetic fields that governed by Laplace
equation. These could markedly enhance the capabilities in thermal sensing,
thermal imaging, thermal-energy storage, thermal packaging, thermal therapy,
and more domains beyond.
