Facebook Reality Labs Develops Wearable Haptic Device to Enhance Interactions with Mobile Interfaces

Researchers working with Facebook Reality Labs and UC Santa Barbara have developed the PneuSleeve, a fabric-based haptic device meant to be worn on the forearm and render a variety of haptic stimuli, including compression, skin stretch, and vibration. The sleeve is designed using a series of embroidered, stretchable tubes and actuators, generating stimuli by controlling pneumatic pressure within the tubes. The team posits that the integration of soft haptic devices such as this into garments can improve their usability for daily computing interactions.

Sleeve and armband gadgets are positioned to have several advantages among possible wearable haptic interface locations. Sleeves give a reasonable amount of design space and leave the hands free. The team’s PneuSleeve system is a composite structure of fabrics and elastomers, which offer a better fit than rigid metals or thermosets and, therefore, more efficient sensing and transmission of stimuli. The actuator design in the PneuSleeve is Fluidic Fabric Muscle Sheets (FFMS), which operates as inverse pneumatic artificial muscles; at high fluid pressure, the actuator is extended and as pressure decreases the actuator contracts and exerts a force. The full setup consists of six single-channel FFMS actuators: two provide radial compression, and four generate linear stretch, while all six can generate vibration.

In order to render high-quality haptic feedback, the sleeve utilizes a closed-loop controller to regulate grounding compression forces, enabled by a soft force sensor. To achieve this based on the capacitance sensing theory, the sleeve uses a layered structure of dielectrics, electrodes, and insulators for sensors. Each pneumatic actuator is controlled through an individual pressure regulator, proportional control three-way valves with inlet, outlet, and exhaust ports. Each regulator is controlled through an analog output generated via data acquisition device interfaced with a PC. The capacitance of the soft force sensors is measured through a custom-built capacitance sensing board, and the measured capacitance acts as the feedback for closed-loop control of the actuator compression force.

The sleeve base is a highly elastic knit fabric and Velcros, offering a close fit to the skin and safety quick release via Velcro closures. The PneuSleeve is designed for ease of wear and use, and the team envisions uses of such wearable haptic devices to include enhanced UIs, notifications, navigation, movement cueing and guidance in exercise, discrete communication, and gaming. Their studies indicate that sleeve is capable of rendering a rich vocabulary of effects, and is a step toward wearable haptic interfaces, despite current limitations in portability and noise produced by high-frequency operations.