The copper plates conducted heat rapidly to and from the bismuth telluride, thus maintaining the temperature difference.

铜片可以把热量迅速地传递到碲化铋上或从碲化铋上导出，这样就能保持气温差。

They work because certain materials, such as bismuth telluride, generate an electrical potential difference within themselves if one part is hotter than another.

它们之所以能起作用是因为某些材料，比如碲化铋，如果其中一部分比另一部分热，内部就会产生电位差。

The third objective, efficient design, involved sandwiching the nanostructured bismuth telluride between two copper plates and then enclosing the upper plate (the one coated with the light-absorbing oxides) and the bismuth telluride in a vacuum.

第三个目标是高效的设计，它涉及到把纳米级的碲化铋夹在两片铜薄片之间然后把位于上方的薄片（这个薄片被覆盖上了吸收光线的氧化物）和碲化铋封入一个真空内。