Abstract
The design of micromechanical devices that can facilitate large but recoverable deformations requires a mechanical behavior that embosoms hyperelasticity. While multiphoton lithography is the epitome of microscale fabrication, the employed materials demonstrate a linear elastic response accompanied by limited ductility. In this study, we investigate how this hindrance can be circumvented through the design of microscale pantographic structures. Pantographs possess riveting hyperelastic response inherited by their structural design, providing exorbitant reversible deformations. To prove the utility of pantographs in microscale design, finite element analysis simulations are performed to unravel the behavior of the structure as a function of its geometrical parameters. In addition, to evaluate the microscale modeling, specimens are fabricated with multiphoton lithography in a push to pull up configuration to accomplish in situ SEM microindentation tensile testing due to compression. Our findings are adduced to expound how the pantographic structures can embrace hyperelastic response even at the microscale, elucidating their feasibility for structural members in micromechanical devices that require reversible large deformations.
| Original language | English |
|---|---|
| Article number | 101202 |
| Journal | Extreme Mechanics Letters |
| Volume | 43 |
| DOIs | |
| Publication status | Published - Feb 2021 |
Bibliographical note
Publisher Copyright:© 2021
Funding
This research was partially supported by the National Science Foundation, USA (NSF) under the Scalable Nanomanufacturing (SNM) Program, Grand No. 1449305 . The authors thank Dr Vasilia Melissinaki and Dr Maria Farsari, FORTH Greece, for assisting in the fabrication of some of the employed specimens of the present study. The authors also thank Professor P. Hosemann, Department of Nuclear Engineering, University of California, Berkeley, for the availability of his indentation apparatus and Professor David J. Steigmann, Department of Mechanical Engineering, University of California, Berkeley for providing thoughtful feedback regarding the interpretation of the experimental results. The nanoindentation and SEM experiments were conducted at the California Institute of Quantitative Bioscience (QB3 Lab). This research was partially supported by the National Science Foundation, USA (NSF) under the Scalable Nanomanufacturing (SNM) Program, Grand No. 1449305. The authors thank Dr Vasilia Melissinaki and Dr Maria Farsari, FORTH Greece, for assisting in the fabrication of some of the employed specimens of the present study. The authors also thank Professor P. Hosemann, Department of Nuclear Engineering, University of California, Berkeley, for the availability of his indentation apparatus and Professor David J. Steigmann, Department of Mechanical Engineering, University of California, Berkeley for providing thoughtful feedback regarding the interpretation of the experimental results. The nanoindentation and SEM experiments were conducted at the California Institute of Quantitative Bioscience (QB3 Lab).
| Funders | Funder number |
|---|---|
| National Science Foundation | |
| Directorate for Engineering | 1449305 |
| University of California Berkeley |
Keywords
- FEA modeling
- Hyperelasticity
- In situ SEM microindentation
- Mechanical Metamaterials
- Multiphoton lithography
- Pantographic structures
