Pyroelectric behaviour of synthetic biomembrane structures

In an attempt to produce pyroelectric Langmuir-Blodgett films containing biological molecules, dl-α-phosohatidic acid dipalmitoyl, dl-α-phosphatidyl-l-serine dipalmitoyl, l-α-phosphatidylcholine dipalmitoyl and l-α-phosphatidylethanolamine dipalmitoyl have been deposited as alternate-layer films on a two-compartment trough. In addition, 1-docosylamine and 22-tricosenoic acid have also been alternated with the above lipids. Pyroelectric coefficients measured by the quasi-static technique were found to have a maximum value of 0.9 μC m^-2 K^-1, comparable to that of other Langmuir-Blodgett structures. Relative permittivity and dielectric loss values (in the range 10 Hz to 100 kHz) were typically 3 and 0.005, respectively. These data give a maximum pyroelectric figure of merit (pyroelectric coefficient/relative permittivity) of 0.29 μC m^-2 K^-1.