Fig. 5.

Theoretical and experimental design of a resonator for personal temperature fluctuations. a A heat map guiding the design and performance (Q) of a thermal resonance device, provided the dimensionless oscillation frequency $\left(v\right)$ of the ambient temperature bath and the ratio of thermal mass diffusion time scales (R). b Time-averaged power output (P_avg) of thermal resonance devices as a function of the square of the length (L₁) of the dominant thermal mass from experiment (red) and fitted with theory (black) (Methods, Supplementary Note 10). An input, angular temperature oscillation frequency (${\omega }_{\mathrm{f}}$), which corresponds to the frequency of personal temperature oscillations (Fig. 4b), is applied to all systems and is indicated in Supplementary Fig. 13