Stretchable Capacitors that Electrically Luminesce, Sense, and Actuate for Biomimetic Coloration
Abstract
Tough, stretchable display technology is important for many reasons: (i) by conformally wrapping around any object, they can bring attention to or hide sensitive equipment, vehicles, or personnel; (ii) by undergoing large area changes, the displays can be portable yet stretched into large and more visible displays or active camouflage; (iii) it provides a technological pathway towards understanding how cephalopods use their posture, skin texture, and coloration for camouflage and display. The proposed research enabled capabilities to better understand visual perception as it pertains to dynamic camouflage. CephalopodÕs (e.g., octopuses and cuttlefish) make themselves invisible to extremely sophisticated visual predation using dynamic camouflage. Despite their remarkable abilities, these animals use only three types of coloration patterns: Uniform, Mottled, and Disruptive. Overlaid on this color camouflage are many other disguise techniques; the cuttlefish, for example, also uses pattern generation, skin texture, and body posture to disguise or reveal themselves. Though some basic explanations of how these animals perform these maneuvers and when they choose to implement them has recently been explained, true understanding of how to control and use dynamic camouflage in a human context will only be revealed using synthetic systems, instead of animal models. The goal of this proposal was to develop synthetic chromatophores that display color electrically. To create stretchable synthetic chromatophores, we synthesized high density arrays of individually addressable elastomeric light emitting capacitors and used a passive matrix addressing method. We achieved our goals by synthesizing highly extensible, transparent conductors and insulators that can be photopatterned at high resolution. We used microfabrication techniques to pattern hyperelastic light emitting capacitors (HLECs) that increase in size and emit light with applied voltage. We explored the trade-offs between increasing HLEC density and maintaining control authority over each synthetic chromophore. We also explored the HLECs capabilities as tactile sensors. we created a portable power system to operate the HLECs, as well as used them as touch sensors. We applied this system to a spherical haptic interface that simulates the game Simon¨. Further, we extended this concept to a high density spherical sensor surface for recognizing gesture via convolutional neural networks (CNNs). Further application of these skins to soft machines will not only allow them to change color, but also afford closed-loop control over posture. Our results included the first article on hyperelastic light emitting capacitors, resulting in a display with the largest reported strain to failure (>500% linear strain). We also reported the first color changing soft robot that is electrically controlled. These HLECs not only display color on the soft robots, but also sense touch and for feedback control of the crawling soft robot. In order to scale up production and make finer display resolution, we developed a photolithography and transfer printing method to scale up the pixel density of the HLEC display and build a passive matrix controller to display individual pixel light emission.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 04, 2019
- Source ID
- W911NF1510464
Entities
People
- Robert F Shepherd
Organizations
- Army Contracting Command
- Cornell University
- United States Army