Pdms-based stretchable multi-electrode and chemotrode array for epidural and subdural neuronal recording, electrical stimulation and drug delivery

A hopper having a passage through which a medicine can be passed downward is provided. A part of a lower portion of the hopper is a deformable portion having flexibility, and the deformable portion is deformable so as to open and close the passage. According to this configuration, the deformable portion that is a part of the hopper is deformed to open and close the passage. Thus, there is no portion such as an opening and closing plate on which the medicine remains, thereby preventing a gap in which the medicine remains from being formed in the hopper, and preventing the medicine from easily remaining in the hopper.