Bioinspired Tunable Lens with Muscle‐Like Electroactive Elastomers

Abstract

Optical lenses with tunable focus are needed in several fields of application, such as consumer electronics, medical diagnostics and optical communications. To address this need, lenses made of smart materials able to respond to mechanical, magnetic, optical, thermal, chemical, electrical or electrochemical stimuli are intensively studied. Here, we report on an electrically tunable lens made of dielectric elastomers, an emerging class of “artificial muscle” materials for actuation. The optical device is inspired by the architecture of the crystalline lens and ciliary muscle of the human eye. It consists of a fluid‐filled elastomeric lens integrated with an annular elastomeric actuator working as an artificial muscle. Upon electrical activation, the artificial muscle deforms the lens, so that a relative variation of focal length comparable to that of the human lens is demonstrated. The device combined optical performance with compact size, low weight, fast and silent operation, shock tolerance, no overheating, low power consumption, and possibility of implementation with inexpensive off‐the‐shelf elastomers. Results show that combing bioinspired design with the unique properties of dielectric elastomers as artificial muscle transducers has the potential to open new perspectives on tunable optics.

Ultrafast All‐Polymer Electrically Tunable Silicone Lenses

“…The hardness of this silicone places it at the higher end of silicones typically used for DEAs (Young's modulus between 0.1 and 1 MPa), and it therefore enters into the category of harder silicones with lower mechanical loss tangent. Despite its relatively high Young's modulus for a PDMS, the lenses made with this material exhibit the same tuning range shown by similar devices made by Carpi et al with the acrylic elastomer VHB, [ 4 ] a fi nding which is confi rmed by our own characterization of acrylic elastomer-based lenses. This shows that the use of silicone allows for gaining several orders of magnitude in response speed, without sacrifi cing much tuning range.…”

A Simple Dynamic Characterization Method for Thin Stacked Dielectric Elastomer Actuators by Suspending a Weight in Air and Electrical Excitation

“…Figure 11 shows the case of weight M = 52.8 g. When the mass of the weight was M = 34.9 g, similar results were observed except that the resonance frequency was high. The frequency response shows good agreement with the typical characteristics of the second-order transfer function shown in Equation (7). A resonance peak of 23 Hz is clearly confirmed from the gain graph in Figure 11.…”

Electrohydrodynamic-assisted Assembly of Hierarchically Structured, 3D Crumpled Nanostructures for Efficient Solar Conversions

“…Upon annealing, the evaporation of ammonia gives rise to the loss of electrostatic stabilization and rGO sheets pucker to minimize the surface tension. In particular, the advent of locally folded, π-π stacked ridges serves as a structural support to stabilize the overall strained structure and suppress further crumpling as the drying process progresses343536. Predictions from molecular dynamics (MD) simulations of crumpled rGO sheets in an aqueous medium mesh well with experimental observations are suggested in Figure S5.…”