Zinc oxide nanorods (ZnO-NRs) with high-aspect ratios can significantly enhance the voltage output of mechanically flexible piezoelectric materials. A versatile chemical synthesis process for growing long narrow ZnO-NR from nanoparticle (NP) seeds by regulating the polarity of reaction solvents is introduced in this paper. The efficient nanorod (NR) growth method produces large quantities of high-aspect ratio ZnO-NRs in the reaction solvent. For ultra-small NP seeds (AVG 10.54 nm, SD 3.69), the synthesis process creates NRs with a minimal lateral growth (AVG 13.92 nm, SD 4.77) and significant longitudinal growth (AVG 150.85 nm, SD 64.93). The average aspect ratio of ZnO-NRs in the solution is ∼10.8 (SD 2.48). Once synthesized, the ZnO-NRs are mixed with polydimethylsiloxane (PDMS) to create a thin flexible piezoelectric layer/film. The composite polymer material is spin coated on an inkjet printed graphene/carboxymethyl cellulose (G-CMC) interdigitated electrode (IDE) to form the piezoelectric layer. A dielectrophoretic alignment technique is then used to reposition the NR orientations in the composite prior to final polymer curing. In this study, three different piezoelectric composites are investigated and compared: polyhedral NPs (ZnO-NP/PDMS), non-aligned nanorods (ZnO-NR_NA/PDMS), and aligned nanorods (ZnO-NR_A/PDMS). Each composite is deposited on a similar IDE and tested for impact loading and low frequency mechanical bending. Under bending, the NP ZnO-NP/PDMS sensor generated 3–4 mV while the non-aligned NR ZnO-NR_NA/PDMS sensor produced 70–80 mV. In contrast, the horizontally aligned NR ZnO-NR_A/PDMS sensor generated 150–170 mV under the same bending conditions.

高纵横比的氧化锌纳米棒（ZnO-NRs）可以显着提高机械柔性压电材料的电压输出。本文介绍了一种通过调节反应溶剂的极性从纳米粒子（NP）种子中生长长而窄的ZnO-NR的通用化学合成方法。高效的纳米棒（NR）生长方法会在反应溶剂中产生大量高纵横比的ZnO-NR。对于超小NP种子（AVG 10.54 nm，SD 3.69），合成过程会产生具有最小横向生长（AVG 13.92 nm，SD 4.77）和明显纵向生长（AVG 150.85 nm，SD 64.93）的NR。溶液中ZnO-NRs的平均长径比约为10.8（SD 2.48）。合成后，将ZnO-NRs与聚二甲基硅氧烷（PDMS）混合以形成薄的柔性压电层/薄膜。将复合聚合物材料旋涂在喷墨印刷的石墨烯/羧甲基纤维素（G-CMC）叉指电极（IDE）上以形成压电层。然后，在最终聚合物固化之前，使用介电泳对准技术将NR方向重新定位在复合材料中。在这项研究中，研究和比较了三种不同的压电复合材料：多面NPs（ZnO-NP / PDMS），非取向纳米棒（ZnO-NR）_NA / PDMS）和对齐的纳米棒（ZnO-NR _A / PDMS）。每个复合材料都沉积在类似的IDE上，并进行冲击载荷和低频机械弯曲测试。在弯曲下，NP ZnO-NP / PDMS传感器产生3–4 mV，而未对准的NR ZnO-NR _NA / PDMS传感器产生70–80 mV。相反，在相同的弯曲条件下，水平排列的NR ZnO-NR _A / PDMS传感器产生150-170 mV。