Metamaterials Applied to Shape Vibration-based Tactile Feedback.
Fully Soft 3D Metamaterial
The practical implementation of acoustic metamaterials usually requires conventional machining methods or additive manufacturing, thus limiting state-of-the-art solutions to mostly rigid structures and planar arrangements. Here is the first, fully soft, 3D acoustic metamaterial at low frequencies. A network of mesofluidic channels embedded in a 3D-printed hyperelastic lattice create pathways for periodic inclusions of low melting point alloy Galinstan. This strategy enables the creation of large impedance gradients within the volume.
Matrix of Taxels Delineated by Acoustic Metamaterial
Modern high-resolution displays have optical qualities on par with human vision, enabling near lifelike viewing experiences. In contrast, existing surface haptic devices do not support rich multi-touch interactions. This work presents a universal method for the design and optimization of broadband acoustic metamaterials aimed at vibration-based haptics. This approach leverages high-density tungsten inclusions and cutting-edge manufacturing techniques, such as metal 3D printing and silicone coatings, to create subwavelength resonant unit cells.
Localized Ultrasonic Lubrication
Mesoscale metamaterials and phononic crystals can be designed to cause the occurence of band gaps in the ultrasonic domain. These localized phenomena induce fixed boundary conditions that correspond to acoustic mirrors which, in turn, can be used to establish waveguides in thin plates. Ultrasonic lubrication has been successfully applied to create haptic interfaces that operate by modulating the apparent friction of a surface. This work shows that phononic crystals can be designed to localize the modulation of friction in specific portions of the surface of a thin plate, opening novel possibilities for the design of surface haptic interfaces.
Application to Cutaneous Stimulation with Ultrasounds.
Programmable Metamaterial
The dispersive qualities of metamaterials remain fixed after manufacturing, limiting their practical use. Actively tuned arrangements have received growing interest to address this issue. Here is a new class of active metamaterial made from dual-state unit cells, either vibration sources when powered or passive resonators when left disconnected. They possess self-tuning capabilities, enabling deep subwavelength band gaps to automatically match the carrier signal of powered cells, typically around 200Hz. Swift electronic commutations between both states establish the basis for real-time reconfiguration of waveguides and shaping of vibration patterns. This novel metamaterial can readily be made using off-the-shelf smartphone vibration motors, paving the way for a widespread adoption of multi-touch tactile displays.
Fully Soft 3D Metamaterial
The practical implementation of acoustic metamaterials usually requires conventional machining methods or additive manufacturing, thus limiting state-of-the-art solutions to mostly rigid structures and planar arrangements. Here is the first, fully soft, 3D acoustic metamaterial at low frequencies. A network of mesofluidic channels embedded in a 3D-printed hyperelastic lattice create pathways for periodic inclusions of low melting point alloy Galinstan. This strategy enables the creation of large impedance gradients within the volume.
Programmable Metamaterial
The dispersive qualities of metamaterials remain fixed after manufacturing, limiting their practical use. Actively tuned arrangements have received growing interest to address this issue. Here is a new class of active metamaterial made from dual-state unit cells, either vibration sources when powered or passive resonators when left disconnected. They possess self-tuning capabilities, enabling deep subwavelength band gaps to automatically match the carrier signal of powered cells, typically around 200Hz. Swift electronic commutations between both states establish the basis for real-time reconfiguration of waveguides and shaping of vibration patterns. This novel metamaterial can readily be made using off-the-shelf smartphone vibration motors, paving the way for a widespread adoption of multi-touch tactile displays.
Application to Cutaneous Stimulation with Ultrasounds.
Localized Ultrasonic Lubrication
Mesoscale metamaterials and phononic crystals can be designed to cause the occurence of band gaps in the ultrasonic domain. These localized phenomena induce fixed boundary conditions that correspond to acoustic mirrors which, in turn, can be used to establish waveguides in thin plates. Ultrasonic lubrication has been successfully applied to create haptic interfaces that operate by modulating the apparent friction of a surface. This work shows that phononic crystals can be designed to localize the modulation of friction in specific portions of the surface of a thin plate, opening novel possibilities for the design of surface haptic interfaces.
Matrix of Taxels Delineated by Acoustic Metamaterial
Modern high-resolution displays have optical qualities on par with human vision, enabling near lifelike viewing experiences. In contrast, existing surface haptic devices do not support rich multi-touch interactions. This work presents a universal method for the design and optimization of broadband acoustic metamaterials aimed at vibration-based haptics. This approach leverages high-density tungsten inclusions and cutting-edge manufacturing techniques, such as metal 3D printing and silicone coatings, to create subwavelength resonant unit cells.