A general platform of microstructured elastomeric substrates that amplifies the mechano-sensitivity of flexible and stretchable devices. The microstructured elastomeric substrates are constructed as a pair of mirror-symmetric, tapered microrods with opposing tips separated by a small distance on the surface of polydimethylsiloxane (PDMS).
Recent advances in materials that are surface plasmon resonators and responsive to external stimuli have advanced the development of high-end optical devices, such as
- active optical components;
- high resolution displays; and
- multiplexed holograms.
In particular, materials that change their properties based on how much they are stretched or compressed are effective at integrating optical and mechanical functionalities.
Current state-of-the-art surface plasmon resonators are not sensitive enough to detect small mechanical deformations needed for the most common applications. This technology solves the problem by locally increasing the deformations at the resonator, which effectively makes the resonator more sensitive to small deformations.
The resonator consists of a lattice of rods embedded in an elastomer positioned between the tips of two tapered rods. As the two rods are pressed together or brought apart, they deform the lattice. Since the metal components are incompressible relative to the elastomer, the elastomer experiences almost all the applied deformation, significantly increasing its strain.
This amplification can be tuned to a desired value by altering the geometry of the metal-elastomer lattice. The result is a highly sensitive optical sensor or actuator that can detect or be manipulated by externally applied deformations.
- 10x greater stain sensitivity than other state-of-the-art stretchable surface plasmon lattice techniques.
- Tunable strain amplification
- Material flexibility
- Strain gauges
- Optical lenses
Top Figure: A schematic of the fabrication process of the lattice using electron beam lithography (EBL) and elastomer (PDMS) casting. Middle Figure: A schematic of the plasmonic grating with alternating metal – elastomer components. Bottom Figure: Finite element analysis modeling of the strain distribution on the metastructure on the surface of the elastomer in response to a 3% applied strain.
Stage of Development:
- Prototypes developed
- Studies are ongoing to extend the proof-of-concept to wearable devices and sensors
Wenxiang Chen, Wenjing Liu, Yijie Jiang, Mingliang Zhang, Naixin Song, Nicholas J. Greybush, Jiacen Guo, Anna K. Estep, Kevin T. Turner, Ritesh Agarwal, and Cherie R. Kagan. ACS Nano 2018 12 (11), 10683-10692. DOI: 10.1021/acsnano.8b04889