Force detection sensor having a base member with a force receiving surface and another surface with an interdigital electrode

A force detection sensor includes a base member having a first surface subjected to an external force and a second surface having a normal direction different from the first surface, and an inter-digital electrode placed on the second surface. Further, the second surface deforms when the first surface is subjected to the force. Furthermore, the second surface includes a part formed by a surface of a piezoelectric material and the inter-digital electrode is placed in the part. The piezoelectric material is quartz crystal. The second surface is parallel to an electrical axis of the quartz crystal.