OPEN-SOURCE TOOLKIT

Crafting Haptics

Despite decades of advocacy for multi-sensory interaction, touch, our primary mode of physical engagement with the world and a powerful communication modality, remains underexplored in much of the design community. Seeking to foster haptic design exploration, we turned to the practice of drawing for inspiration. Drawing with paintbrushes on canvas is a timeless act of creation. It’s approachable to anyone, and even kids can pick up a brush and explore together. Yet, it holds space for mastery, enabling artists to craft expressive works through tacit knowledge. It also invites improvisation, like a dance between hands, pigments, and playful discovery. What if we could design touch as intuitively as we draw?

This led us to ask:
If the body is the canvas, what might a paintbrush for haptics be?

To explore the intuitive and improvisational qualities of touch design, we introduce the metaphor of “crafting haptics,” which carries two layers of meaning:

• First, since haptics is inherently about touch, we aim to explore the design of expressive haptic interactions directly through hand manipulation, 
as intuitive as clay crafting in a dynamic way.

• Second, we strive to investigate how designers, using approachable, analog materials, can craft with “care, skill, and ingenuity” – Merriam-Webster's definition of “Craft,” potentially leading to virtuoso performances in haptic design.

Shape-Kit

Shape-Kit is a novel hybrid haptic design toolkit that embodies our “crafting haptics” metaphor. By leveraging human power and hand dexterity, the Shape-Kit analog tool can transduce and amplify (or minify) human touch behaviors into pin-based haptic sensations through a flexible and long transducer, enabling free-form sensorial exploration of touch across the body or on another person’s body. Shape-Kit allows designers to experiment with various crafting approaches, from bare-hand manipulation to using hand-held props, similar to sculpting with clay. Textures and materials can be attached to the output end, much like paintbrushes, which can have different tips for dipping in various pigments. Just as paintings can be photographed, we employ an ad-hoc method to capture and digitize crafted touch patterns, which could be applied to computational pin-based haptic interfaces. 

Mechanism and System Design

Shape-Kit analog tool features two spring-back shape displays connected by flexible Bowden cables. Dark markers are applied to the internal cables to show the displacement. By mounting the tracking module, the crafted shape patterns can be captured with a webcam and digitized through computer vision. We also developed the Shape-Kit GUI, which provides real-time digital simulation and allows designers to record touch patterns digitally. A programmable shape display is built to demonstrate how the digitized touch patterns can be tangibly replayed.

DESIGN SESSIONS

To characterize the “crafting” of haptics with Shape-Kit, we conducted six small group design sessions with designers and artists. Inspirational topics and prompts were provided to spark the ideation, while props and materials were prepared to enhance tactile exploration. Our findings highlight the richness and subtle variations in touch design achieved through diverse crafting methods, from bare-hand techniques to leveraging the affordances, properties, and textures of the props and materials.

Collaborative and Embodied Haptic Design

Shape-Kit opens up a new space for collaborative design of touch. While touch is often considered intimate, Shape-Kit’s long transducer and pin-filtered interaction establish a comfortable distance and neutralize the sensation. This enhances openness in bodily exploration that is playful, curious, and respectful. 

Beyond verbal and visual communication, Shape-Kit’s bi-directional feedback enables embodied collaboration, allowing ideas to be communicated through touch. Designers fluidly switch roles between crafter, holder, and perceiver to ideate, prototype, iterate, and compose touch together. The design experiences of on-body haptics with Shape-Kit become an embodied dialogue, fostering shared sense-making and deepening the resonance of touch-based interaction.

TEAM

Ran Zhou, Jianru Ding, Chenfeng Gao, Wanli Qian, Benjamin Erickson, Madeline Balaam, Daniel Leithinger, and Ken Nakagaki

PUBLICATION

Ran Zhou, Jianru Ding, Chenfeng Gao, Wanli Qian, Benjamin Erickson, Madeline Balaam, Daniel Leithinger, and Ken Nakagaki. 2025. Shape-Kit: A Design Toolkit for Crafting On-Body Expressive Haptics (Accepted to CHI2025, Best Paper Honorable Mention) Pre-print

ACKNOWLEDGEMENT