Electrical, thermoelectric and thermophysical properties of hornet cuticle

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 sigma = 8.5 x 10(-5) Omega(-1) cm(-1). The thermoelectric figure of merit is computed. Implications for possible exploitation as a natural thermoelectric heat pump are discussed.