A power generator includes a top, a support, a bearing, a rotating device and a transforming device. The method further includes providing sampled voltages from the first terminal of the bipolar device to a modulator to produce a modulator output signal, filtering the modulator output signal to produce a filtered output signal using a back-end filter having an impulse response, and determining a temperature in response to the filtered output signal. Cells may be grown in cell culture media that includes liquid crystals that exhibit little or no toxicity to cells.