an electrically driven signal unit is adapted for one - step assembly or injection molding with a device housing to vibrate , flex , beep or emit audio signals , or to sense and provide tactile feedback or control . the signal unit is a package with one or more active areas each containing a layer of ferroelectric or piezoelectric material , connected by inactive areas which may position , align and conduct electricity to the active areas . the active areas may be coupled over a region to transmit compressional , shear or flexural wave energy into the housing , or may contact at discrete regions while bending or displacing elsewhere to create inertial disturbances or impulses which are coupled to create a tactile vibration of the housing . the unit may be assembled such that the housing , the sheet or discrete areas thereof form a bender to provide tactile or sub - auditory signals to the user , or may be dimensioned , attached and actuated to produce audio vibration in the combined structure and constitute a speaker . in other embodiments one or more active regions of piezo material are attached to thin or movable wall regions of the unit to sense strain and , in conjunction with a conditioning circuit , produce electrical switching or control signals for the device . other embodiments include devices having a tight tolerance between a housing wall and a signal module , and devices having one or more through - holes located on the housing wall . the invention also includes electroactive sheet structures having a polymer block , bracket or functional body formed therearound , which serves as a mounting , coupling or functional operating structure for the driven device .