Abstract: A thermal to electrical energy conversion device has freestanding thin or thick films of thermoelectric materials, n or p type or both, extending from thermally conducting and electrically insulating substrates. The freestanding thermoelectric elements exploit up to two orders of magnitude higher free convective heat transfer coefficient and thermal resistance. The combined effect is very large temperature differential not possible with prior art unless an auxiliary cooling mechanism (pumped liquid or fanned air) is used. The large temperature differential results in higher efficiency and power output. Methods of making these thermal electric conversion devices are also disclosed.