The disclosure relates to an apparatus for electrostatically adhering grains to a planar substrate comprising:. A light-emitting chip can be mounted on one of the first and the second mounting surfaces, which extend in a substantially same level and balanced shapes with respect to each other to be used as external electrodes. A light source and a sound source may be placed at the transmitter device. Related devices are also discussed. A first portion and a second portion of the first layer of electrically insulative material is removed. When the second request signal cannot be received, the portable device retransmits the first response signal from the transmitter with a frequency that differs from the one of the plurality of frequencies.