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coMorphing Stool

Design Implementation

Prototyping Process


coMorphing stool is a shape-changing thing that can change its shape in response to the change of surrounding light (see Figure 3). Here, we call the coMorphing stool a computational thing by considering that it can embody the qualities of transformation and vitality. Transformation describes that the physical surface of the coMorphing stool can temporally express subtle shape changes. coMorphing stool is vital because the embedded actuator can make subtle sounds when deforming the elastic fabric. To enhance daily entanglements with shape change, we purposefully designed a hollowed space between the enclosure and the fabric. Unlike everyday stools, the volume of the coMorphing stool can increase with the dimming of the surrounding light and vice versa. The goal of deformalizing the interactivity of the coMorphing stool was to embody the proposed questions. Generally, we want to support independent and longitudinal field deployments of the coMorphing stool as a research product.

We speculated on possible input factors by programming with alternative digital materials. Our initial step was to test an ultrasonic sensor because it could capture nuanced motions and activities happening around the coMorphing stool. However, we found the HC-SR04 sensor cannot precisely transfer detected signals to an Arduino nano board. This challenge stimulated us to program with different sound sensors (KY-037 and KY-038) because the sound created by (non)human beings can activate the coMorphing stool. Activating the coMorphing stool with nuanced surrounding sound might garner unique and intimate attention from co-speculators. Yet, the detected analogue values cannot perfectly match sound values made a few meters away. Addressing this challenge resulted in the final selection of a photoresistor as the input device of the coMorphing stool. With this sensor, the transformation of the surrounding light (both natural and domestic) can also trigger the shape change of the coMorphing stool. In the long-term, the coMorphing stool may express shape change in different temporal patterns along with the transformation of daytime across seasons. Therefore, co-speculators who live with the coMorphing stool may develop diverse reflective insights in relation to technological mediation over time.

We highlighted the portability and rechargeability of the coMor- phing stool by designing a power management system. As the input voltage of the actuator is 12V, we deliberately utilized a power bank with 12V output for testing. We installed a power switch on the wooden base to enhance the safety of use. coMorphing stool can be plugged in and fully charged in around 10 hours. Consequently, people who live with coMorphing stool can freely move it across rooms in their homes.

We produced a small batch of 5 coMorphing stools as shape- changing things for the field study. The shape- changing interface of the coMorphing stool is upholstered in a piece of white-colored spandex with hollowed dot patterns. We adopted cork material to fabricate the seat of the stool as it has a low heat transfer property, which can sustain daily entanglements with the seat across seasons in comfortable and unobtrusive ways. We installed the photoresistor in the centre of the seat to invite long-term experiments and speculations with the stool, such as placing a book on the seating surface. Three supporting poles were intentionally mounted to the wooden base to support the weight of an adult and thus enhance the robustness of the form enclosure. The base of the coMorphing stool was crafted with solid wood, which can resist pressures applied to the stool. We then applied linseed oil to the sanded wooden base and seat to protect it from scratches, dirt, and wear. Thus, making these parts more robust and potentially long-lasting. Ultimately, we assembled all the physical parts and digital materials.

Field Deplyment


Zhong, C., Wakkary, R., Odom, W., Wiberg, M., Chen, A Y. S., & Oogjes, D. Investigating Long-Term Mediated Experiences of a Shape-Changing Thing: A Field Study of the coMorphing Stool. In Proceedings of the 2023 CHI Conference on Human Factors in Computing Systems.

Zhong, Ce. "Designing and Deploying Shape-changing Artifacts in Everyday Settings Over Time: Extending Practices and Methodologies for Materiality in HCI." In Companion Publication of the 2021 ACM Designing Interactive Systems Conference, pp. 1-4. 2021.

Zhong, Ce. "Investigating Materiality as a Frame for Supporting Creative and Organic Relations with Shape-changing Artifacts in Everyday Settings Over Time." In Creativity and Cognition, pp. 1-5. 2021.

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