Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, United States.
Nano Lett. 2011 Mar 9;11(3):1331-6. doi: 10.1021/nl104412b. Epub 2011 Feb 15.
The development of a method for integrating highly efficient energy conversion materials onto soft, biocompatible substrates could yield breakthroughs in implantable or wearable energy harvesting systems. Of particular interest are devices which can conform to irregular, curved surfaces, and operate in vital environments that may involve both flexing and stretching modes. Previous studies have shown significant advances in the integration of highly efficient piezoelectric nanocrystals on flexible and bendable substrates. Yet, such inorganic nanomaterials are mechanically incompatible with the extreme elasticity of elastomeric substrates. Here, we present a novel strategy for overcoming these limitations, by generating wavy piezoelectric ribbons on silicone rubber. Our results show that the amplitudes in the waves accommodate order-of-magnitude increases in maximum tensile strain without fracture. Further, local probing of the buckled ribbons reveals an enhancement in the piezoelectric effect of up to 70%, thus representing the highest reported piezoelectric response on a stretchable medium. These results allow for the integration of energy conversion devices which operate in stretching mode via reversible deformations in the wavy/buckled ribbons.
将高效能量转换材料集成到柔软、生物兼容的基底上的方法的发展，可能会在可植入或可穿戴的能量收集系统中取得突破。特别感兴趣的是那些能够适应不规则、弯曲表面的器件，并且能够在可能涉及弯曲和拉伸模式的重要环境中运行。先前的研究已经表明，在将高效压电纳米晶体集成到柔性和可弯曲基底上取得了重大进展。然而，这种无机纳米材料在机械上与弹性体基底的极端弹性不兼容。在这里，我们提出了一种克服这些限制的新策略，即在硅橡胶上生成波浪状的压电带。我们的结果表明，在不发生断裂的情况下，波的幅度可以适应最大拉伸应变的数量级增加。此外，对褶皱 ribbons 的局部探测表明，压电效应增强了高达 70%，这代表了在可拉伸介质上报告的最高压电响应。这些结果允许通过波浪/褶皱 ribbons 的可逆变形，集成以拉伸模式运行的能量转换器件。
