Authors:

Paul A Loughlin

Date Created:

Not specified

Course Title:

Professor:

Not specified

About Paper:

Programmable soft metamaterials introduce new opportunities to leverage geometrical nonlinearities, enabling adaptability, shape morphing, and mechanical computing. These metamaterials offer an alternative approach for controlling soft robotics, mechanical information processing, signal filtering, and tactile sensing, driven by the mechanical response of the structure rather than a traditional computer. Metasheets composed of repeating dome units have garnered interest due to their capabilities, such as exhibiting different energy minima, inversion path dependency, multiple global stable shapes, and shape-changing properties. In this work, we explore a class of multistable metastructures composed of repeating dome units that enable strain amplification and sensing. We achieve this by combining soft materials, Thermoplastic Polyurethane (TPU), with conductive Polylactic Acid (PLA) filaments, which facilitate strain field amplification and measurement using stress produced by dome inversion. We utilize Fused Deposition Modeling (FDM) 3D printing to embed the sensor into the structure, ensuring reliable and consistent measurements. Various sensor geometries and locations are used to address two main hurdles encountered during the manufacturing process. First, we mechanically couple the TPU and PLA, which do not meld together, to produce a uniform membrane. Second, we relocated the sensors from the top of the sheet to the underside to improve printing quality. Additionally, we examine the proximity of the sensor to the dome units to prevent sensor failure due to high stresses, ensuring more reliable and consistent measurements. By solving these issues, full-scale testing can be conducted with a sheet of domes with embedded sensors, allowing for strain measurements across the entire metasheet surface and potentially distinguishing between different external forces. Keywords: Mechanical Sensing; Flexible Sensors; Bistability

Source:

Purdue University / 2024

Topics:

No topics listed

Co-authors:

Paul A Loughlin