This underrepresented minority (URM) supplement project is proposed for the PhD support for Corey Carlos with a research focus on atomic force microscopy (AFM) study of the mechanical and piezoelectric properties of flexible piezoelectric microstructures, and further improve his professional readiness toward his next academic career step. This research activity represents a logical extension of the fundamental goals outlined in the parent grant (R01HL157077). Specifically, this project explores an alternative approach toward intracardiac mechanical energy harvesting, aimed by the parent grant. While the parent grant focuses on using a sliding mode triboelectric nanogenerator design, this supplemental project will examine a new type of electromechanical materials that may serve as an alternative and promising material candidate for achieving intracardiac energy harvesting. The goal of this supplement project is therefore to test a 3D-printed piezoelectric microlattice that can offer designed mechanical flexibility and strong piezoelectric output under small pressure fluctuations. This study will provide an additional set of novel material options for the design of intracardiac biomechanical energy harvesters. This research goal will be achieved through two specific aims. In specific Aim 1, flexible piezoelectric films with microlattices will be fabricated by 3D printing using a novel piezoelectric composite, which can yield desired structural integrity and well-aligned piezoelectric phase. AFM will be used to characterize the localized mechanical property, and establish a relationship between the microstructure and flexibility to reveal the strain distribution when the microlattice is under pressure. In specific Aim 2, the local piezoelectric property from the microlattice will be characterized by the AFM-based piezoelectric force microscopy (PFM) mode, and correlate to the mechanical behaviors at different locations of the microlattice. Combining these characterization results, we will achieve synergistic optimization of mechanical and piezoelectric properties satisfying the requirements of flexible implantable nanogenerator devices. In the URM supplement project, Mr. Corey Carlos will perform the basic 3D print fabrication and carry out all the proposed AFM-based characterization under the mentoring of PI Wang. This supplement project offers an excellent opportunity for Corey to establish more experiences on soft bio-related materials characterizations and development. It will also help Corey to extend his research portfolio to the areas of biomedical materials and devices – an extremely promising direction that he wants to build his academic career. In the supplement project, Corey will also participate multiple teaching and output programs, including the First Year Faculty Teaching Academy (FYFTA), the WiscProf: Future Faculty in Engineering Workshop, and the Graduate Engineering Research Scholars (GERS) program.