Piezo-Actuated MOF@SAW Devices

Oberhofer/Volkmer/Wixforth财团将开发新型压电响应协调框架（CF），该框架将放置在表面声波（SAW）设备上，以刺激和研究电场诱导的框架动力学。将合成新型压电响应型CFs，包括非结合分子转子（uR），空间限制在刚性CFs中（uR@rCFs），刚性CFs中的轴向安装转子（amR） （amR@rCFs），以及显示巨大压电响应的铰链CFs。MOF@SAW压电响应型CFs器件的构建一方面要满足驱动框架的双重目的（即CFs的巨大压电畸变，安装在CFs上的偶极转子的受激旋转），另一方面还要满足介电响应函数的检测。不同层次的理论研究将有助于模拟框架化合物的自发极化及其介电响应特性。对于后者，将执行密度泛函紧密结合方法以及基于力场的CFs矢量或激活质量输运现象的MD模拟。为了准确地描述框架建筑单元的内部静电相互作用以及其对外部静态和时间相关电场的响应，将引入一种新的极化力场。

The Oberhofer/Volkmer/Wixforth consortium is going to develop novel piezo-responsive coordination frameworks (CF) which will be placed on Surface-Acoustic Wave (SAW) devices in order to stimulate and to investigate electric field-induced framework dynamics. Novel piezo-responsive CFs will be synthesized, including unbound molecular rotors (uR), spatially confined in rigid CFs (uR@rCFs), axially mounted rotors (amR) in rigid CFs (amR@rCFs), as well as hinged CFs displaying a giant piezoelectric response.MOF@SAW devices of piezo-responsive CFs shall be constructed serving a dual purpose of framework actuation on one hand (i.e. giant piezoelectric distortion of CFs, stimulated rotation of CF-mounted dipolar rotors), as well as detection of the dielectric response function, on the other hand. Theoretical investigations at different levels shall serve to model the spontaneous polarization of framework compounds and their dielectric response characteristics. For the latter, density functional tight binding approaches as well as force-field based MD simulations of vectorial or activated mass transport phenomena in the CFs will be performed. A novel polarisable force field will be introduced in order to describe the internal electrostatic interactions of the framework’s building units as well as its response towards external static and time-dependent electrical fields accurately.