Rapid Prototyping, Soft Tech, Physical Interaction Design
2 months
Background
Haptic Compass is a wearable vest equipped with actuators that enable two-dimensional navigation. This project aims to explore the role of haptic interaction in enhancing the navigation experience through effective and intuitive navigation cues.
Project Goal
Motivated by the limitations of traditional visual-centric navigation tools, particularly in challenging environmental conditions and for users with diverse abilities, our proposed solution leverages haptic feedback to offer a more intuitive and hands-free navigational experience.
The goal is to use body storming sessions and rapid prototyping methods to quickly prototype, evaluate, and validate the initial ideas of using haptic feedback to improve the experience of city navigation.
Process & Role
Exploration - Which body area has the potential to develop a haptic interface?
The initial design phase of the haptic compass focused on selecting the optimal location on the human body for the haptic interface. We tested various body parts by simulating haptic feedback patterns during walking and running. While palms and forearms initially showed promise, they posed challenges due to their movement and orientation variability.
The back emerged as the most effective location due to its stable position and ample surface area, enabling clear and consistent haptic feedback. This choice also minimized user variability and allowed for versatile two-dimensional haptic encoding.
Exploration - Which type of haptic pattern is more intuitive and has the potential to convey more information?
The cutaneous rabbit illusion, or CRE, is a tactile trick in which rapid taps on different skin areas create the sensation of continuous movement. In the prototyping and user testing stages, we decided to explore two types of haptic patterns further.
Prototyping - The "Vest"
The vest prototype was conceptualized with adjustable straps and a back-covering fabric to accommodate different body sizes. The design drew inspiration from posture-correcting vests, using stretchy, thin fabric to enhance vibration perception.
Back: A 5x5 grid of haptic actuators was sewn into the back fabric, which was layered to avoid direct contact with users' skin. This grid allows for the precise delivery of haptic feedback.
Pouch: A sturdy canvas pouch was integrated to house electronic components, ensuring functionality and aesthetic consistency.
Belt and Straps: Adjustable belts and straps, reinforced with velcro and 3D-printed sliders, ensured various users' secure fit and adaptability.
Prototyping - Control Unit
Actuators: The prototype utilized 25 haptic linear resonant actuators arranged in a 5x5 matrix. These actuators were chosen for their compact size, steady vibration, and low power consumption.
Circuitry: The actuators were controlled by an Arduino UNO microcontroller, supplemented by a 16-channel multiplexer. LEDs were added for debugging and visual feedback.
Evaluation - Is it really effective with haptic feedback?
Experiment Group
Participants undertook a 3-6 minute walk using the haptic compass to navigate an unfamiliar location, simulating exploration in a new city or route.
Control Group
A control group navigated the same route using audio directional instructions from a navigation app (e.g., Google Maps) to compare against the haptic compass. This method ensured no physical device was handled by participants, maintaining passive instruction delivery.
Summary & Closing Thoughts
Thoughts for further improvement:
Considering the potential to integrate with Map App: Integrating the haptic compass with a map application, such as Google Maps, could significantly enhance its practicality for everyday navigation, making it a viable tool for mass adoption.
Calibration and Intensity: Refining the calibration of the haptic grid and ensuring consistent vibration intensity across the vest will be crucial for improving the accuracy and reliability of directional cues.
Design for the recognition during the user flow: Enhancing the design of vibration cues, potentially through varied patterns or targeted stimulation of specific body regions, could lead to more intuitive and immediate recognition of navigational signals.
