OC-CG1
Barium titanate piezoelectric flexible materials enabled by hierarchically porous graphite for application as mechanical energy harvesters and sensors Mariana Rodriguesa, Artur Baetaa, Maxim Ivanova, Yifei Liub, Donglei Fanc, Paula M. Vilarinhoa, Paula Ferreiraa a Department of Materials and Ceramic Engineering, CICECO – Aveiro Institute of Material, University of Aveiro, 3810-193 Aveiro, Portugal. bMaterials Science and Engineering Program, Texas Materials Institute, The University of Texas at Austin, Austin, TX 78712, USA. cDepartment of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA. E-mail: pcferreira@ua.pt
Wearable sensors are becoming increasingly important in off-site monitoring. In this context, the development of piezoelectric flexible materials turned to be urgent. In this work, multi-level porous graphite is used as support for the synthesis of BaTiO3. Nanostructured BaTiO3 has been growth by “bottom-up” approach within the pores of graphite foams. Hydrothermal colloidal suspensions and sol gel solutions are being impregnated in three dimensional foams. In the case of the hydrothermal colloidal suspension, the impregnation was carried out with (VA) and without (NV) voltage assistance (V = ± 0,5 V). The composite was treated to 400 °C to hydroxyl groups and water and to enable a second impregnation step to fulfil the pores. The sol gel solutions were left in contact with the foam till all solution was absorbed. After, rapid thermal annealing and microwave-assisted furnace heat treatments were performed to crystallize tetragonal BaTiO3. In both cases, mainly tetragonal barium titanate was achieved as confirmed by XRD and Raman. High-resolution SEM imaging was performed to understand the structural and morphological features in relation to the synthesis conditions. Evaluation of piezoelectric and electric properties of these fabricated nanostructures was carried out and will be discussed.
Graphite foam
Figure 1. SEM micrographs of graphite,
Impregnated graphite foam with BaTiO3 barium titanate nanoparticles and impregnated foam. BaTiO3
Acknowledgments: This work was developed within the scope of the project CICECO Aveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020 and in the scope of the Piezoflex Project UTA-EXPL/NPN/0015/2019, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. PF is thankful to FCT for the IF/00300/201.5.
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