About

I invent, build, and evaluate novel interaction technologies that open the door to wholly new computing experiences, with a particular focus on tactile interfaces. The sense of touch remains underutilized when it comes to how we interact with computers. I believe the primary reason for this is the lack of sophisticated and functional haptic displays and the underdevelopment of haptic design practice and science needed to successfully implement and proliferate them.

Research topics

• Computer Science
• Simulation
• Materials science
• Composite material
• Human–computer interaction
• Mechanical engineering
• Operating system
• Computer graphics (images)
• Electrical engineering
• Thermodynamics
• Physics
• Engineering
• Telecommunications

Selected publications

• Sensitivity at the Edges of the Finger Enables Mixed Reality Force Feedback

  IEEE Transactions on Haptics · 2026-01-01

  articleOpen accessSenior author

  We introduce a new paradigm for rendering highforce sensations by stimulating the edges of the fingerpad rather than the central contact surface. This non-blocking approach preserves natural finger use, enabling simultaneous physical and virtual interactions. To investigate its feasibility, we proposed a mechanotransduction mechanism and conducted biomechanical and psychophysical studies. Our results show that the fingerpad edges are nearly as sensitive as the center under low forces, become roughly 117% more sensitive under moderate forces, and maintain sensitivity at higher forces. The edges also exhibit increased stiffness and tolerate higher forces before discomfort. Furthermore, the left edge exhibited approximately 143% higher sensitivity than the right edge in the right hand. Using these insights, we built a compact wearable device that provides multiDOF force feedback without blocking the fingerpad and demonstrated its use in VR/AR scenarios. These findings support edgebased stimulation as a viable approach for high-force, scalable haptic feedback in mixed reality and teleoperation systems.

  PublisherDOI

• Mag-Chain: Reconfigurable 6-DOF Tangible Interfaces Using Magnetic Chains

  2026-03-07

  articleOpen accessSenior author

  We present a novel, simple method for creating reconfigurable 6-degree-of-freedom (DOF) tangible interfaces using diametrically magnetized cylindrical magnetic chains, termed Mag-Chains. These paired magnets support stable 3-DOF motions—bending, twisting, and sliding—with passive restoring forces, while constraining other axes. This enables rich multi-magnet dynamics and expands the design space for magnetic structures. We experimentally characterize Mag-Chains behavior across multiple design parameters and summarize practical design guidelines. We also integrate sensing using either 6-DOF optical tracking or simple contact switches. Building upon these findings, we developed a fully functional 6-DOF tangible input device featuring a large workspace and passive haptic feedback along all six axes—three translational and three rotational. To demonstrate versatility, we present three applications: interactive toys, a clip-on joystick with mobile camera tracking, and a miniature finger-worn controller. Our results highlight the potential of Mag-Chains as a compact platform for building sensor-integrated and reconfigurable tangible interfaces with rich motion expressiveness.

  PublisherDOI

• HaptiCoil: Soft Programmable Buttons with Hydraulically Coupled Haptic Feedback and Sensing

  2025-04-24 · 5 citations

  articleOpen accessSenior author
  PublisherDOI

• Pushing the Boundary: Force Sensitivity at the Edges of the Finger for Mixed Reality Haptics

  2025-07-08 · 2 citations

  articleSenior author

  We introduce an alternative paradigm for rendering high-force sensations to the fingertip by stimulating the edges of the fingerpad rather than the bare finger. This non-blocking approach enables virtual and augmented touch while preserving natural finger use, allowing simultaneous digital and physical haptic interactions. To explore this concept, we developed a plausible mechanotransduction working principle, conducted biomechanical and psychophysical experiments, and built a small wearable prototype device. Our findings suggest that the finger's edges are nearly as sensitive as the center for low forces (0.7 N), are about 150% as sensitive to moderate forces (1 to 3 N), and exhibit extended sensitivity at high forces (up to 5 N). Additionally, edge regions show nearly 140% of the stiffness of the center, and are capable of tolerating higher forces before participants report discomfort. These results support the viability of edges-based stimulation for nuanced, high-force haptic feedback, which could have implications for mixed reality and tele-operated interactive systems.

  PublisherDOI

• 96‐1: <i>Invited Paper:</i> Flat Panel Haptics: Embedded Electroosmotic Pumps for Scalable Shape Displays

  SID Symposium Digest of Technical Papers · 2024-06-01

  article1st authorCorresponding

  The flat, featureless nature of touch screen displays has meant keyboard text entry is slower and more error‐prone than on mechanical counterparts, and has also introduced negative side effects in demanding settings like automotive. Ideally, we could maintain the graphical flexibility afforded by displays, but carry over the tactile benefits of physical keyboard keys and buttons. Flat panel haptic displays have the potential to achieve this. We present a new type of shape‐changing display using embedded electroosmotic pumps (EEOPs). Our pumps are 1.5mm in thickness, and allow complete stack‐ups under 5mm with the opportunity to become much thinner. Our EEOPs can move their entire volume's worth of fluid in 1 second, and apply pressures of +/‐50kPa. This is enough to create dynamic, mm scale tactile features on a surface.

  PublisherDOI

• DynaButtons: Fast Interactive Soft Buttons with Analog Control

  2024-04-07 · 8 citations

  articleSenior author

  While mechanical buttons are ubiquitous, their haptic response is fxed, reducing interface fexibility and precluding an avenue for rich feedback. Here, we describe a new type of dynamic button, or DynaButton, which can vary its visual and haptic response via rapid shape change. To achieve this, we made several advances in the performance of embedded electroosmotic pumps: we increased core pump speed >300% over prior work, demonstrated closed-loop control, and investigated analog output that varies in response to pressure and force inputs. We validated our system with a physical characterization and performed a series of stimuli recognition studies to validate the expressivity and discriminability of three regimes of button interaction.

  PublisherDOI

• Expressive, Scalable, Mid-air Haptics with Synthetic Jets

  ACM Transactions on Computer-Human Interaction · 2023-12-01 · 7 citations

  articleOpen accessSenior author

  Non-contact, mid-air haptic devices have been utilized for a wide variety of experiences, including those in extended reality, public displays, medical, and automotive domains. In this work, we explore the use of synthetic jets as a promising and under-explored mid-air haptic feedback method. We show how synthetic jets can scale from compact, low-powered devices, all the way to large, long-range, and steerable devices (Figure 1 ). We built seven functional prototypes targeting different application domains to illustrate the broad applicability of our approach. These example devices are capable of rendering complex haptic effects, varying in both time and space. We quantify the physical performance of our designs using spatial pressure and wind flow measurements and validate their compelling effect on users with stimuli recognition and qualitative studies.

  PublisherOA PDFDOI

• Fluid Reality: High-Resolution, Untethered Haptic Gloves using Electroosmotic Pump Arrays

  2023-10-20 · 63 citations

  articleOpen accessSenior author

  Virtual and augmented reality headsets are making significant progress in audio-visual immersion and consumer adoption. However, their haptic immersion remains low, due in part to the limitations of vibrotactile actuators which dominate the AR/VR market. In this work, we present a new approach to create high-resolution shape-changing fingerpad arrays with 20 haptic pixels/cm2. Unlike prior pneumatic approaches, our actuators are low-profile (5mm thick), low-power (approximately 10mW/pixel), and entirely self-contained, with no tubing or wires running to external infrastructure. We show how multiple actuator arrays can be built into a five-finger, 160-actuator haptic glove that is untethered, lightweight (207g, including all drive electronics and battery), and has the potential to reach consumer price points at volume production. We describe the results from a technical performance evaluation and a suite of eight user studies, quantifying the diverse capabilities of our system. This includes recognition of object properties such as complex contact geometry, texture, and compliance, as well as expressive spatiotemporal effects.

  PublisherDOI

• Flat Panel Haptics: Embedded Electroosmotic Pumps for Scalable Shape Displays

  2023 · 51 citations

  1st authorCorresponding
  • Computer Science
  • Computer Science
  • Computer graphics (images)

  Flat touch interfaces, with or without screens, pervade the modern world. However, their haptic feedback is minimal, prompting much research into haptic and shape-changing display technologies which are self-contained, fast acting, and offer millimeters of displacement while only being only millimeters thick. We present a new, miniaturizable type of shape-changing display using embedded electroosmotic pumps (EEOPs). Our pumps, controlled and powered directly by applied voltage, are 1.5mm in thickness, and allow complete stackups under 5mm. Nonetheless, they can move their entire volume’s worth of fluid in 1 second, and generate pressures of +/-50kPa, enough to create dynamic, millimeter-scale tactile features on a surface that can withstand typical interaction forces (<1N). These are the requisite technical ingredients to enable, for example, a pop-up keyboard on a flat smartphone. We experimentally quantify the mechanical and psychophysical performance of our displays and conclude with a set of example interfaces.

  PublisherOA PDFDOI

• Electro-actuated Materials for Future Haptic Interfaces

  2023-10-27 · 3 citations

  article

  Electro-actuated materials (EAMs) have received wide attention within material science and soft robotics for their ability to dynamically change physical properties, such as shape and stiffness, in response to electrical stimuli. While researchers have begun exploring the haptic characteristics of EAMs, their integration into Human-Computer Interaction (HCI) shows challenges, including limited commercial availability and a lack of interdisciplinary knowledge exchange. This workshop specifically focuses on electrostatic (ES), soft electrohydraulic (SEH), and electroosmotic (EO) actuators. By bringing together researchers in the field, we aim to facilitate the exchange of findings, techniques, fabrication practices, and tacit knowledge within the HCI community. The workshop combines interactive demos, focused discussions, and hands-on ideation, providing a platform to explore the haptic potential of EAMs, identify key challenges and opportunities, and envision how these programmable materials can unlock new haptic interactions and interfaces.

  PublisherDOI

Frequent coauthors

• J. Edward Colgate

  Northwestern University

  10 shared

• Chris Harrison

  Carnegie Mellon University

  9 shared

• Joe Mullenbach

  8 shared

• Michael A. Peshkin

  Northwestern University

  6 shared

• Anne Marie Piper

  University of California, Irvine

  4 shared

• Vivian Shen

  Carnegie Mellon University

  4 shared

• Tucker Rae-Grant

  Carnegie Mellon University

  2 shared

• Ahad M. Rauf

  2 shared

Labs

• Interactive Display LabPI

Awards & honors

• IEEE Technical Commitee on Haptics Early Career Award Winner