Stretchable smart patch: Serpentine network connected functional node array with enhanced acoustic emission detectability and thermo-activated drug delivery functions

This paper presents a multifunctional and stretchable smart patch. This patch contains the node array with coated piezoelectric lead zirconate titanate (PZT) film for sensing acoustic emission (AE) wave and thermally activated Poly(N-isopropylacrylamide) PNIPAM nodes for delivering drug. The PZT sensing node array is realized on a thin flexible titanium sheet with serpentine network electrically connected (Fig. 1). This design has two unique properties: (1) the serpentine network allows the node array to stretch in an arbitrary planar direction; (2) the normal force of AE detection head coupling to the sensing object can be enhanced while the patch stretched. The fabrication and testing of the designed serpentine network AE sensing module along with the temperature controlled drug release element are reported.