An article includes a body that has a coating thereon. The head portion includes a bellows-like acoustic action member for creating acoustic wave action as it moves in and out in response to an acoustic driving force. The redundant address decoder includes a fuse box having a plurality of make-links for decoding an address of a defect cell and a redundant word line selection circuit for selecting a word line of a redundant cell corresponding to the address of the defect cell in response to a signal output from the fuse box. The hydrogel matrix comprises about 3 to about 150 mM of polar amino acids.