Electrical, thermoelectric and thermophysical properties of hornet cuticle

Abstract

Seebeck effect (thermo-emf ), thermal conductivity and electrical conductivity of social hornet cuticle were measured in a direction perpendicular to the cuticular surface. The obtained value of the Seebeck coefficient (S) was about 3 ± 0.5 mV K −1 and its sign corresponded to an n-type (electronic) conductivity. Hornet cuticle is shown to be a fairly good heat insulator, with recorded values of the heat conductivity as low as 0.1-0.2 W m −1 K −1 . The measured value of the electrical conductivity in the linear regime is σ = 8.5 × 10 −5 −1 cm −1 . The thermoelectric figure of merit is computed. Implications for possible exploitation as a natural thermoelectric heat pump are discussed.

Study of hysteretic thermoelectric behavior in photovoltaic materials using the finite element method, extended thermodynamics and inverse problems

“…In [2], a similar behavior was observed in the cuticle of the oriental hornet Vespa Orientalis. This cuticle seemly works as a thermoelectric heat pump for the cooling of the hornet body, and as a solar energy harvesting allowing the hornet to increase its activity in the presence of strong insolation, [3].…”

“…Two very different results were observed: As discussed in the introduction, for samples that present a hysteretic behavior it is difficult to assign a representative Seebeck coefficient: α was calculated from the heating branch in [2] and from the common diagonal slope of different loops obtained applying different ∆T 's in [1], fitting the experimental results to a unique α:…”

“…These parameters are usually denominated transport properties and, in general, depend on temperature as reported in [11]. As discussed in the introduction, the ENET considers dissipative fluxeṡ q,j in the classical entropy balance (2). Therefore and according to [12], the entropy production becomes:…”

“…For the second challenge, an empirical procedure without solid theoretical basis was proposed in [1], consisting on an analytical fitting of the experimental curves. An alternative explanation was proposed in [2], measuring the Seebeck coefficient uniquely at the heating branch.…”

Multiphysics and Thermodynamic Formulations for Equilibrium and Non-equilibrium Interactions: Non-linear Finite Elements Applied to Multi-coupled Active Materials

“…[125] for more applications. A thermoelectric behavior has recently been observed in the Oriental hornet (Vespa orientalis) cuticular abdomen, [48]. Figure 3 shows several thermoelectric material devices and the hornet.…”