Chemical Haptics:
Rendering Haptic Sensations via Topical Stimulants
Team: Jasmine Lu, Ziwei Liu, Jas Brooks, Pedro Lopes
In this paper, I explored how chemical ingredients could be applied to the skin and stimulate haptic sensations such as tingling, numbing, cooling, warming, and stinging. We explored how this could be used for interactive contexts like VR and built two devices for this use-case (one for the cheeks, one for the forearm). This paper was accepted to UIST2021 and can be read here.
Paper Abstract. We propose a new class of haptic devices that provide haptic sensations by delivering liquid-stimulants to the user’s skin; we call this chemical haptics. Upon absorbing these stimulants, which contain safe and small doses of key active ingredients, receptors in the user’s skin are chemically triggered, rendering distinct haptic sensations. We identified five chemicals that can render lasting haptic sensations: tingling (sanshool), numbing (lidocaine), stinging (cinnamaldehyde), warming (capsaicin), and cooling (menthol). To enable the application of our novel approach in a variety of settings (such as VR), we engineered a self-contained wearable that can be worn anywhere on the user’s skin (e.g., face, arms, legs). Implemented as a soft silicone patch, our device uses micropumps to push the liquid stimulants through channels that are open to the user’s skin, enabling topical stimulants to be absorbed by the skin as they pass through. Our approach presents two unique benefits. First, it enables sensations, such as numbing, not possible with existing haptic devices. Second, our approach offers a new pathway, via the skin’s chemical receptors, for achieving multiple haptic sensations using a single actuator, which would otherwise require combining multiple actuators (e.g., Peltier, vibration motors, electro-tactile stimulation). We evaluated our approach by means of two studies. In our first study, we characterized the temporal profiles of sensations elicited by each chemical. Using these insights, we designed five interactive VR experiences utilizing chemical haptics, and in our second user study, participants rated these VR experiences with chemical haptics as more immersive than without. Finally, as the first work exploring the use of chemical haptics on the skin, we offer recommendations to designers for how they may employ our approach for their interactive experiences.
Integrating Living Organisms in Devices to Implement Care-based Interactions
Team: Jasmine Lu, Pedro Lopes
In this paper, we explore how embedding a living organism (in this case a slime mold, *Physarum Polycephalum*) as a functional component of a device, changes the user-device relationship. In our design, the user needs to care for the living organism (through providing food and water) in order for the device to work. This paper was accepted to UIST2022 and can be found here.
Paper Abstract. Researchers have been exploring how incorporating care-based interactions can change the user’s attitude & relationship towards an interactive device. This is typically achieved through virtual care where users care for digital entities. In this paper, we explore this concept further by investigating how physical care for a living organism, embedded as a functional component of an interactive device, also changes user-device relationships. Living organisms differ as they require an environment conducive to life, which in our concept, the user is responsible for providing by caring for the organism (e.g., feeding it). We instantiated our concept by engi- neering a smartwatch that includes a slime mold that physically conducts power to a heart rate sensor inside the device, acting as a living wire. In this smartwatch, the availability of heart-rate sensing depends on the health of the slime mold—with the user’s care, the slime mold becomes conductive and enables the sensor; conversely, without care, the slime mold dries and disables the sensor (resuming care resuscitates the slime mold). To explore how our living device was perceived by users, we conducted a study where partic- ipants wore our slime mold-integrated smartwatch for 9-14 days. We found that participants felt a sense of responsibility, developed a reciprocal relationship, and experienced the organism’s growth as a source of affect. Finally, to allow engineers and designers to expand on our work, we abstract our findings into a set of technical and design recommendations when engineering an interactive device that incorporates this type of care-based relationship.
Team: Jasmine Lu, Beza Desta, K D Wu, Romain Nith, Joyce Passananti, Pedro Lopes
In this paper, we explore how electronics design tools could support processes of recycling electronic components from e-waste during the design process. Inside any device that might typically become e-waste, one can find dozens to hundreds of reusable components. Despite the abundance of components in e-waste, existing electronic design tools assume users will buy all components anew. To tackle this, we created a tool called ecoEDA that facilitates the process of reusing electronic components from e-waste during the design process through integration with KiCad. We released this tool as open source, showcase several projects made with e-waste, and also ran a user study with the tool. This paper was presented as part of the UIST2023 proceedings and can be found here.
Paper Abstract.
The amount of e-waste generated by discarding devices is enor- mous but options for recycling remain limited. However, inside a discarded device (from consumer devices to one’s own prototypes), an electronics designer could fnd dozens to thousands of reusable components, including microcontrollers, sensors, voltage regulators, etc. Despite this, existing electronic design tools assume users will buy all components anew. To tackle this, we propose ecoEDA, an interactive tool that enables electronics designers to explore recycling electronic components during the design process. We accomplish this via (1) creating suggestions to assist users in identifying and designing with recycled components; and (2) maintaining a library of useful data relevant to reuse (e.g., allowing users to fnd which devices contain which components). Through example use-cases, we demonstrate how our tool can enable various pathways to recycling e-waste. To evaluate it, we conducted a user study where participants used our tool to create an electronic schematic with components from torn-down e-waste devices. We found that participants’ designs made with ecoEDA featured an average of 66% of recycled components. Last, we refect on challenges and opportunities for building software that promotes e-waste reuse.
Team: Jasmine Lu, Pedro Lopes
HCI primarily focuses on designing and understanding device interactions during one segment of their lifecycles—while users use them. Leaving significant space overlooked: when devices are no longer “useful” to the user, such as after breakdown or obsolescence. We argue that HCI can learn from experts who upcycle e-waste and give it second lives, exploring their practices through the lens of unmaking both when devices are physically unmade and when the perception of e-waste is unmade once waste becomes, once again, useful.
This paper will be presented at CHI2025 and can be found here.
Paper Abstract.
The proliferation of new technologies has led to a proliferation of unwanted electronic devices. E-waste is the largest-growing consumer waste-stream worldwide, but also an issue often ignored. In fact, HCI primarily focuses on designing and understanding device interactions during one segment of their lifecycles—while users use them. Researchers overlook a significant space—when devices are no longer “useful” to the user, such as after breakdown or obsolescence. We argue that HCI can learn from experts who upcycle e-waste and give it second lives in electronics projects, art projects, educational workshops, and more. To acquire and translate this knowledge to HCI, we interviewed experts who unmake e-waste. We explore their practices through the lens of unmaking both when devices are physically unmade and when the perception of e-waste is unmade once waste becomes, once again, useful. Last, we synthesize findings into takeaways for how HCI can engage with the issue of e-waste.
ProtoPCB: Reclaiming Printed Circuit Board E-waste as Prototyping Material
︎ [ paper (to appear soon) ]
Team: Jasmine Lu, Pedro Lopes
PCBs often easily become e-waste because they are designed for a specific circuit. To extend the utility of PCBs, we introduce a computational approach to enable reusing PCBs as prototyping material to implement new circuits. Our tool takes a user’s desired circuit schematic and analyzes its components and connections to find methods of creating the user’s circuit on discarded PCBs (e.g., e-waste, old prototypes). We believe our tool offers: (1) a new approach to prototyping with electronics beyond the limitations of breadboards and (2) a new approach to reducing e-waste during electronics prototyping.
This paper will be presented at CHI2025.
Paper Abstract.
We propose an interactive tool that enables reusing printed circuit boards (PCB) as prototyping materials to implement new circuits — this extends the utility of PCBs rather than discards them as e-waste. To enable this, our tool takes a user’s desired circuit schematic and analyzes its components and connections to find methods of creating the user’s circuit on discarded PCBs (e.g., e-waste, old prototypes). In our technical evaluation, we utilized our tool across a diverse set of PCBs and input circuits to characterize how often circuits could be implemented on a different board, implemented with minor interventions (trace-cutting or bodge-wiring), or implemented on a combination of multiple boards — demonstrating how our tool assists with exhaustive matching tasks that a user would not likely perform manually. We believe our tool offers: (1) a new approach to prototyping with electronics beyond the limitations of breadboards and (2) a new approach to reducing e-waste during electronics prototyping.
