Exothermic chemical reactions from nitrocellulose are coupled onto Sb2Te3 (antimony telluride) and Bi2Te3 (bismuth telluride) layers to generate self-propagating oscillating thermopower waves. P-type Sb2Te3 and N-type Bi2Te3 are employed due to their large Seebeck coefficients, high electrical conductivities and their complementary semiconducting properties. Sources based on both materials exhibit high power to mass ratios: up to 0.6 kW kg−1 for Sb2Te3 and 1.0 kW kg−1 for Bi2Te3. Having both P- and N-type semiconductors in the system, the combination of the outputs can be used for generating sources with polarities alternating in time.
