Detecting Thermal Cloaks via Transient Effects

Journal Article · Thu Sep 08 00:00:00 EDT 2016 · Scientific Reports

DOI:https://doi.org/10.1038/srep32915· OSTI ID:1624853

Sklan, Sophia R. ^[1]; Bai, Xue ^[2]; Li, Baowen ^[3]; Zhang, Xiang ^[4]

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1. Massachusetts Institute of Technology (MIT), Cambridge, MA (United States). Dept. of Physics; Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering; Univ. of Colorado, Boulder, CO (United States). Dept. of Mechanical Engineering
2. National University of Singapore, Republic of Singapore. Dept. of Electrical and Computer Engineering, Dept. of Physics and Centre for Computational Science and Engineering, and NUS Graduate School for Integrative Sciences and Engineering
3. Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering; Univ. of Colorado, Boulder, CO (United States). Dept. of Mechanical Engineering
4. Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering; Univ. of California, Berkeley, CA (United States). NSF Nanoscale Science and Engineering Centre; Lawrence Berkeley National Lab (LBNL), Berkeley, CA (United States). Materials Sciences Div.

Recent research on the development of a thermal cloak has concentrated on engineering an inhomogeneous thermal conductivity and an approximate, homogeneous volumetric heat capacity. While the perfect cloak of inhomogeneous κ and inhomogeneous ρc_p is known to be exact (no signals scattering and only mean values penetrating to the cloak’s interior), the sensitivity of diffusive cloaks to defects and approximations has not been analyzed. We analytically demonstrate that these approximate cloaks are detectable. Although they work as perfect cloaks in the steady-state, their transient (time-dependent) response is imperfect and a small amount of heat is scattered. This is sufficient to determine the presence of a cloak and any heat source it contains, but the material composition hidden within the cloak is not detectable in practice. To demonstrate the feasibility of this technique, we constructed a cloak with similar approximation and directly detected its presence using these transient temperature deviations outside the cloak. Due to limitations in the range of experimentally accessible volumetric specific heats, our detection scheme should allow us to find any realizable cloak, assuming a sufficiently large temperature difference.

• Research Organization: Lawrence Berkeley National Lab (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Science Foundation (NSF)
• Grant/Contract Number: AC02-05CH11231; 1122374
• OSTI ID: 1624853
• Journal Information: Scientific Reports, Vol. 6, Issue 1; ISSN 2045-2322
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English

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