Complex Materials, Department of Materials , ETH Zürich , Vladimir-Prelog-Weg 5 , 8093 Zürich , Switzerland.
School of Mechanical Engineering , Purdue University , 585 Purdue Mall , West Lafayette , Indiana 47907 , United States.
ACS Nano. 2019 Apr 23;13(4):4752-4760. doi: 10.1021/acsnano.9b01095. Epub 2019 Apr 9.
Mechanosensing is ubiquitous in natural systems. From the skin ridges of our finger tips to the microscopic ion channels in cells, mechanosensors allow organisms to probe their environment and gather information needed for processing, decision making, and actuation. Despite technological advances in synthetic mechanosensing, it remains challenging to achieve this functionality at the scale of large stiff structures where both the amount of data to sense locally and the diversity of input stresses that the sensors have to withstand require highly tunable systems. Filtered sensing using mechanical displacement is an effective strategy developed by organisms to cope with large sets of stimuli. Inspired by this biological strategy, we fabricate bistable elements that can passively filter mechanical inputs, translate them into electrical signals, and be reset to their original sensing state using an external magnetic field. These multiple functionalities are achieved using hierarchically structured composites that can be arranged in large-area arrays. The filtering capability and fast passive response of our mechanosensors are experimentally demonstrated using simple electrical circuits and magnets. Thanks to their scalability and applicability to a wide range of material systems, these low-power sensors are avenues for the fabrication of load-bearing structures that are able to sense, compute, communicate, and autonomously adapt in response to external magneto-mechanical stimuli.
机械感知在自然系统中无处不在。从我们指尖的皮肤脊到细胞中的微观离子通道,机械传感器使生物体能够探测其环境并收集处理、决策和驱动所需的信息。尽管在合成机械传感方面取得了技术进步,但在大型刚性结构的规模上实现这种功能仍然具有挑战性,因为需要高度可调的系统来感知局部的大量数据和传感器必须承受的各种输入应力。利用机械位移进行滤波感知是生物体应对大量刺激的一种有效策略。受此生物策略的启发,我们制造出了可以被动过滤机械输入的双稳态元件,将它们转换为电信号,并使用外部磁场将其重置为原始感应状态。这些多功能性是通过可以布置在大面积阵列中的分层结构复合材料实现的。我们的机械传感器的滤波能力和快速被动响应通过简单的电路和磁铁进行了实验验证。由于其可扩展性和适用于广泛的材料系统,这些低功率传感器为制造能够感知、计算、通信并根据外部磁机械刺激自主适应的承载结构提供了途径。