Magnetoelectric and magnetomechanical interactions in compliant composite materials

柔顺复合材料中的磁电和磁力相互作用

• 批准号: 389008375
• 负责人: Professor Dr. Mikhail Chamonine
• 金额: --
• 依托单位: Fakultät Elektro- und Informationstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/389008375?language=en
• 关键词: Magnetoelectric; magnetomechanical; interactions; compliant; composite

Conventional magnetoelectric (ME) composite materials comprise layers of piezoelectric ceramic or single-crystal materials and ferromagnetic metals or alloys. The efficiency of ME interaction is the highest when the modulation frequency of the external magnetic field coincides with eigenfrequencies of mechanical oscillations in the composite structure due to resonance enhancement of deformations in the piezoelectric layer. Since the constitutive solid-state materials have large elastic constants, the corresponding resonance frequencies are also high (typically in the range betwen 1 kHz and 300 kHz). However, for some applications, e.g. for low-frequency magnetic field sensing or vibration energy harvesting, it would be advantageous to have the mechanical resonance frequency of the composite structure much lower, e.g. in the frequency range below 100 Hz. At the present state of technology, compliant (flexible) polymer materials are promising candidates for realization of flexible ME composites. In general, polymer based smart materials are very interesting for MEMS and microfluidic applications because of the advantages of mechanical flexibility, lower fabrication cost and faster processing over silicon based devices. The purpose of this project is to develop enhanced ME layered composite materials, preferably completely made of compliant (flexible) polymers, and to investigate in detail their ME properties. To optimize ME composite materials, the relevant properties of constitutive materials must be investigated as well. Magnetoactive elastomers (MAEs) will be used as magnetostrictive component. These magnetoactive elastomers comprise micrometer-sized magnetic particles (e.g. iron) dispersed in a soft elastomer (e.g. polydimethylsiloxane, PDMS) matrix. Magnetostrictive properties of MAEs will be investigated in the broad temperature range between -60°C and +60°C and they will be related to the increase of the dynamic shear modulus in external magnetic fields, known as magnetorheological or field-stiffening effect. The Wiedemann effect in MAEs will be investigated as a specific manifestation of magnetostriction. MAE layers must be further combined with compliant (flexible) PE materials to form ME composite materials. Different possibilities of implementing PE layers will be explored. In particular, it is envisaged to investigate PDMS-based micro-structured ferroelectric structures, polyvinylidene fluoride (PVDF) and piezo fibre based sandwich composites. Temperature dependencies of ME interaction efficiency in fabricated composite structures will be determined experimentally. These temperature characteristics must be explained from temperature dependencies of constitutive materials. The achieved progress in understanding of ME and magnetomechanical phenomena in developed soft composite materials could open the way for new applications in smart structures.

常规磁电（ME）复合材料包括压电陶瓷或单晶材料以及铁磁金属或合金的层。当外部磁场的调制频率与复合结构中机械振荡的特征频率相吻合时，我的相互作用的效率最高，这是由于增强了压电层中变形的谐振。由于组成型固态材料具有较大的弹性常数，因此相应的共振频率也很高（通常在1 kHz和300 kHz的范围内）。但是，对于某些应用，例如对于低频磁场灵敏度或振动能量收集，使复合结构的机械谐振频率要低得多，例如在低于100 Hz的频率范围内。在目前的技术状态下，合规（柔性）聚合物材料是候选柔性ME复合材料的候选者。通常，由于机械柔韧性，较低的制造成本和比基于硅的设备的加工速度，基于聚合物的智能材料对于MEMS和微流体应用非常有趣。该项目的目的是开发增强的ME分层复合材料，最好完全由合规（柔性）聚合物制成，并详细研究其ME特性。为了优化我的复合材料，也必须研究组成材料的相关特性。磁活性弹性体（MAE）将用作磁对称成分。这些磁活性弹性体包括分散在软弹性体（例如聚二甲基硅氧烷，PDMS）基质中的千分尺磁颗粒（例如铁）。 MAE的磁性特性将在-60°C和 +60°C之间的广泛温度范围内进行研究，它们将与外部磁场中动态剪切模量的增加有关，即磁性Heological Heological heological heological或田间渗透效果。 Wiedemann在MAE中的效应将作为磁截图的特定表现进行研究。必须将MAE层与合规（柔性）PE材料进一步结合，以形成我的复合材料。将探索实现PE层的不同可能性。特别是，它设想研究基于PDMS的微结构铁电结构，聚偏二氟化物（PVDF）和压电纤维基夹层组成。 ME相互作用效率在制造的复合结构中的温度依赖性将通过实验确定。这些温度特征必须从本构材料的温度依赖性中解释。在理解我的理解和发达的软复合材料中的磁力学现象方面取得的进展可能为智能结构中的新应用开辟道路。