Collaborative Research: Space Charge Induced Flexoelectric (SCIF) Transducers: A New Technology to Eliminate the Environmental Cost of Leaded Piezoelectric Transducers

合作研究：空间电荷感应柔性 (SCIF) 传感器：消除含铅压电传感器环境成本的新技术

• 批准号: 2247453
• 负责人: Shad Roundy
• 金额: $ 22.5万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247453&HistoricalAwards=false
• 关键词: Collaborative; Research; Space; Charge; Induced

Non-technical descriptionPiezoelectric materials convert mechanical force to electrical voltage and vice-versa. These materials are used in precision sensors, optics, acoustic transmitters and receivers, and energy harvesting devices. Most high-performance piezoelectric materials contain lead. It is estimated that the annual worldwide production of lead-containing piezoelectric materials is between 1250 and 4000 tons. The lead contained in these materials represents an environmental risk all along the value chain, from mining to end device disposal, and is increasingly subject to health, safety, and environmental legislation. This project will develop an environmentally benign replacement for piezoelectric transducers. This new technology will be based on a newly observed phenomenon in semiconducting materials including silicon. In this project, the team of researchers will fabricate nano-structured silicon devices that can replace lead-containing piezoelectric materials. In addition to creating a replacement for lead-containing piezoelectrics, the study of this new technology will enhance the scientific community’s understanding of electrical-mechanical interaction in solid materials more generally. The newly created devices will be transformative for sensing, actuation, and energy harvesting applications.Technical descriptionLead zirconate titanate (PZT), or other lead-containing piezoelectrics, are widely used in precision sensors, actuators for optics, acoustic transmitters and receivers, energy harvesters, and precision positioning devices. Despite the significant environmental concerns, there is still no good replacement for PZT. In this project we will make use of a newly observed phenomenon, space charge induced flexoelectricity, to create a high-performance alternative to PZT transducers. Flexoelectricity refers to electrical polarization of a dielectric material in response to strain gradient. It has recently been observed that semiconducting materials, including silicon, with insulating interfaces (i.e., space charge materials) exhibit enhanced flexoelectricity. In this project the team of researchers will fabricate arrays of nano-structured silicon pyramids to create and study space charge induced flexoelectric transducers. In tandem with the fabrication work, the investigators will create a computational framework for simulating the interaction between the strain gradient, the electric field, and the diffusion of mobile charge carriers. This computational framework will enable a detailed investigation into the mechanisms driving space charge flexoelectricity and allow optimization of transducers. Such transducers could have effective piezoelectric coefficients an order of magnitude higher than state-of-the-art micro-scale piezoelectric materials. Given that they are made from silicon, they fill the need for a non-toxic, environmentally benign replacement to high performance piezoelectric transducers. Space charge induced flexoelectric transducers will be transformative for a broad range of smart materials applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

压电材料将机械力转换为电压，反之亦然。这些材料用于精密传感器、光学器件、声学发射器和接收器以及能量收集设备。大多数高性能压电材料都含有铅。据估计，全世界含铅压电材料的年产量在1250至4000吨之间。这些材料中所含的铅在价值链的整个沿着（从采矿到终端设备处置）都存在环境风险，并且越来越多地受到健康、安全和环境法规的约束。该项目将开发一种对环境无害的压电换能器替代品。这项新技术将基于在包括硅在内的半导体材料中新观察到的现象。在这个项目中，研究小组将制造纳米结构的硅器件，可以取代含铅的压电材料。除了替代含铅压电体之外，这项新技术的研究还将增强科学界对固体材料中机电相互作用的更普遍的理解。新开发的器件将在传感、驱动和能量收集应用方面具有革命性意义。技术说明锆钛酸铅（PZT）或其他含铅压电材料广泛应用于精密传感器、光学致动器、声学发射器和接收器、能量收集器和精密定位设备。尽管存在重大的环境问题，但仍然没有PZT的良好替代品。在这个项目中，我们将利用一个新观察到的现象，空间电荷诱导的挠曲电，以创建一个高性能的替代PZT换能器。挠曲电性是指介电材料响应于应变梯度的电极化。最近已经观察到具有绝缘界面（即，空间电荷材料）表现出增强的挠曲电性。在这个项目中，研究小组将制造纳米结构的硅金字塔阵列，以创建和研究空间电荷诱导的挠曲电换能器。在制造工作的同时，研究人员将创建一个计算框架，用于模拟应变梯度、电场和移动的电荷载流子扩散之间的相互作用。这种计算框架将使详细的调查机制驱动空间电荷flexoelectricity，并允许优化的换能器。这种换能器可以具有比现有技术的微尺度压电材料高一个数量级的有效压电系数。由于它们是由硅制成的，因此它们满足了对高性能压电换能器的无毒、环保替代品的需求。空间电荷感应挠曲电传感器将为广泛的智能材料应用带来变革。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。