Haptic Symbol Got Your Back:
Dynamic On-body Vibrotactile
Patterns as Notification Cues

Master Project 2020 | 5 months Industrial Design, University of Technology Eindhoven, NL
Skill: haptic interaction, design research, design tools
Project Coach: Mathias Funk
Expert: Manus VR
Exhibition: DDW2020 - UpClose&Personal

How to support designers to create haptic symbols (a set of designed spatial-temporal vibrotactile patterns) that link to specific abstract information in Human-Computer Interaction? We got your back! In this study, I propose a design tool for the initial exploration and iteration of vibrotactile patterns as a new interaction modality and provide a stepping stone for further research in haptic interaction design.

“We have the ability to discriminate tactile patterns and process and learn them just as we do for recognizing letters or words in speech and vision.” —— Sherrick, 1975, The art of tactile communication

Research Through Design Process

In this project, the Constructive Design Research method was applied. The process of the five-month project is instructed by the IDEO Human-centered design model.


The Tool Kit

Vocabulary Items

Describe & Visualize

Co-Design

Haptic Symbols

This formative co-design session finally yielded eight vibrotactile patterns mapped to eight information items, by summarizing the common ground and characteristics of each design concept from the participants.

Prototyping

a) Using Adafruit 16-Channel PWM Driver Shield, to individually control multiple motors by Pulse Width Modulation signals, b) hand-made cube to enclose the Eccentric Rotating Mac (ERM) vibration motor to make sure it works when attached to fabric; c) the first iteration; d) pilot testing; e) soldering and neaten the circuit; f) arrange and attach the vibration motor to the garment; g) making and finishing the garment.

User Study and Expert Evaluation

In this section, I briefly summarize the evaluation, including usability test, expert evaluation and data analysis. More detailed information can be found in the report. User Study: Distinguishability of the patterns: accessed by the recognition rate Affordance: measured by the mapping rate with the information items Subjective workload and user experience: rated through a Likert Scale questionnaire modified from the UEQ questionnaire. The participants were encouraged to think aloud and speak. A semi-structured interview was conducted at the end of the session. The notes were informally analyzed based on the content analysis method.

Expert Evaluation The aim of the expert evaluation is not limited to the design concept itself, but also gathering feedback about the application and further development. Five experts were recruited from Manus VR, three wearable designers (one lead director, one for generating concepts, one for bringing concept to prototype), one industrial designer and one lead director focusing on wearable hardware engineer. The expert evaluation was conducted in the office of Manus VR in Eindhoven. The interview notes were analysed by content analysis tools.