Element

An element comprising:

• an upper electrode having an uneven structure;
• a flexible intermediate layer;
• a lower electrode closely attached to the intermediate layer;
• and
• a lower cover arranged on a surface of the lower electrode opposite to a surface of the lower electrode closely attached to the intermediate layer, wherein
• the element is configured to generate an electrical signal due to contact and separation between the upper electrode and the intermediate layer, and
• the lower electrode and the lower cover take shapes fittable to the uneven structure when the upper electrode and the intermediate layer come into contact with each other.