Mechanically Adjustable Radiative Heat Transfer Between hBN and α-MoO3 Plates

Nanoscale thermal regulation plays a critical role in many applications, especially in nano-opto-electromechanical systems (NOEMS). In this work, we investigate the near-field radiative heat transfer (NFRHT) in an asymmetric system, consisting of a uniaxial hexagonal boron nitride (hBN) and a biaxial
$\alpha $
-MoO3 plates. We predict that the strain-induced shift frequency change of hBN can remarkably change the coupling of hyperbolic modes (HMs) of hBN and
$\alpha $
-MoO3, enabling efficient thermal regulation. Specifically, thanks to the strain-induced adjustable HMs of hBN, the regulation ratios for
${z}$
[010],
${x}$
[100], and
${y}$
[001] directions of
$\alpha $
-MoO3 reach 47.5, 58.8, and 13.3, respectively. Furthermore, considering the highly tunable surface plasmon polaritons (SPPs) of graphene, we also study the regulation effect with graphene coverage. Results show that with the increase of
$\mu $
, the regulation ratio for hBN and G/
$\alpha $
-MoO3 shows the maximum of 9.2 when
$\mu $
= 0.1 eV compared to other asymmetric systems. This work is beneficial for a deep understanding on the photon tunneling in asymmetric systems and facilitates efficient thermal management in NOEMS by strain engineering.