Fabrication and analysis of PbTiO3 hollow nano truss structure for breaking the elastic limit and piezoelectric coefficient탄성 한계와 압전 계수 증가를 위한 내부가 비어 있는 nano truss 구조의 PbTiO3 제작 및 분석
Piezoelectric materials have been widely investigated in haptic applications due to their ability to convert mechanical stimuli into electrical signals. However, piezoelectric materials have tradeoff between piezoelectric coefficient and elastic limit which limits their wide application to haptic devices. Here we fabricated PbTiO$_3$ hollow nanostructure with mesoscale body centered tetragonal (BCT) symmetry to break this tradeoff. We used two separate processing schemes, namely PbO gas reaction with TiO$_2$ thin films to fabricate PbTiO$_3$ thin film and proximity field nanopatterning (PnP) to create PbTiO$_3$ hollow nanostructure. The thickness of TiO$_2$ was increased to 20, 30, and 50 nm, and the characteristics were analyzed according to the thickness. The structure stability and crystallinity of PbTiO$_3$ was evaluated through XRD, SEM, and TEM, the piezoelectric modulus was measured through AFM, and the elastic modulus was measured through the compression test. This research will provide insight into optimum piezoelectric materials with both high piezoelectric coefficient and high elastic limit, which could be used in various haptic applications.