  Simultaneously guiding electromagnetic waves and heat flow at any incidence
angle to smoothly bypass some electromagnetic/thermal sensitive elements is a
key factor to ensure efficient communication and thermal protection for an
on-chip system. In this study, an omnidirectional on-chip
electromagnetic-thermal cloak is proposed. Firstly, a holey metallic plate with
periodic array of subwavelength apertures is designed by optical surface
transformation to realize an omnidirectional electromagnetic cloaking module
for on-chip electromagnetic signal. Secondly, a two-layer ring-shaped
engineered thermal structure is designed by solving Laplace equation to realize
an omnidirectional thermal cloaking module for in-chip heat flow. Finally,
these two cloaking modules are combined elaborately to achieve cloaking effect
for both the electromagnetic waves and thermal fields simultaneously from any
detecting direction, thus protecting the build-in electromagnetic/thermal
sensitive elements without disturbing the external electromagnetic/thermal
signal. The proposed electromagnetic-thermal cloak may have potential advantage
in dealing with omnidirectional electromagnetic compatibility/shielding and
multi-directional thermal management/dissipation of an on-chip system.
