A thermoelectric conversion element includes a pair of electrodes and a pyroelectric material, which is a ferroelectric layer, sandwiched between the pair of electrodes. Carbohydrate absorption inhibitor in this invention is characterized that the effective component is an alcohol extract of evening primrose seed. The patterned electric conductive layer partially covers the insulation layer. When the display devices are detachably connected along side edges to expose the display portion of the display devices, the expandable mobile device provides a larger display area and can be used as a tablet. The first and second positioning components are configured to engage each other so as to align the plurality of ink receiving portions and the plurality of ink supply portions relative to each other.