Elastocaloric TiNi-based Films and Devices

弹热 TiNi 基薄膜和器件

• 批准号: 226996689
• 负责人: Professor Dr. Manfred Kohl
• 金额: --
• 依托单位: Institut für Mikrostrukturtechnik (IMT)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/226996689?language=en
• 关键词: Elastocaloric; TiNi; based; Films; Devices

This proposal represents the renewal of the joint project 'Elastocaloric Ti-Ni based Films and Devices' aiming at solid-state cooling using TiNi-based shape memory films. During the first funding period we demonstrate that SMA film devices show large temperature changes up to -16 K, high cycling frequencies faster than 1 Hz as well as ultra-high fatigue resistance (> 10 million cycles). These properties will be further explored in innovative cooling devices using the potential of thin film and MEMS technology. The underlying mechanisms for long term stability are investigated by focusing on the influence of precipitates, austenite/martensite crystallographic compatibility and grain size (E. Quandt). The results are then transferred to other material systems by investigating elastocaloric effect size and efficiency to identify well suited materials for small-scale elastocaloric cooling applications. Two approaches in demonstrator development are pursued based either on solid/solid heat transfer or on heat transfer in a liquid medium (M. Kohl). Solid/solid heat transfer will be improved by adapting the shape and force of contacting surfaces as well as by investigating the influence of thermally conductive layers and surface topography due to micro/nano-machining. Heat transfer in a liquid medium will be investigated for a regeneration-based elastocaloric device. Finite element simulations are performed on the device level taking into account the thermo-mechanical coupling of SMA film device and its environment. Demonstrator systems (M. Kohl and E. Quandt) will be fabricated and evaluated with respect to cooling power and long-term operation. The potential for microcooling applications will be assessed for the case of a lab-on-chip system.

该提案代表了旨在使用TiNi基形状记忆薄膜进行固态冷却的联合项目“弹性热Ti-Ni基薄膜和器件”的更新。在第一个资助期内，我们证明了SMA薄膜器件显示出高达-16 K的大温度变化，快于1 Hz的高循环频率以及超高的抗疲劳性（> 1000万次循环）。这些特性将在利用薄膜和MEMS技术潜力的创新冷却设备中进一步探索。长期稳定性的潜在机制，研究的重点是沉淀，奥氏体/马氏体晶体相容性和晶粒尺寸的影响（E。Quandt）。然后将结果转移到其他材料系统，通过调查弹热效应的大小和效率，以确定适合小规模弹热冷却应用的材料。验证器的研制有两种方法，一种是基于固体/固体传热，另一种是基于液体介质中的传热（M。科尔）。固/固传热将通过调整接触表面的形状和力以及通过研究由于微/纳米加工的导热层和表面形貌的影响来改善。本文将研究一种基于再生的弹性热装置在液体介质中的传热。考虑到SMA薄膜器件与环境的热-机械耦合，在器件级上进行了有限元模拟。演示系统（M. Kohl和E. Quandt）将进行制造，并就冷却能力和长期运行进行评估。微冷却应用的潜力将被评估的情况下，一个实验室芯片系统。