# ArrayTac: A Closed-loop Piezoelectric Tactile Platform for Continuously Tunable Rendering of Shape, Stiffness, and Friction

arXiv: https://arxiv.org/abs/2603.13829 · HTML: https://mlsanity.com/paper/2603.13829/

## Key facts

- No citing papers in the map yet (data through 14 Oct 2026).
- Builds on 5 of its 57 references that are in the map.
- First posted on arXiv 14 Mar 2026.

## Builds on (most cited first, 5 of 5)

- [Segment Anything](https://mlsanity.com/paper/2304.02643/) (2023)
- [Depth Anything V2](https://mlsanity.com/paper/2406.09414/) (2024)
- [ArrayBot: Reinforcement Learning for Generalizable Distributed Manipulation through Touch](https://mlsanity.com/paper/2306.16857/) (2023)
- [Tactile Perception of Electroadhesion: Effect of DC versus AC Stimulation and Finger Moisture](https://mlsanity.com/paper/2409.16936/) (2024)
- [FiDTouch: A 3D Wearable Haptic Display for the Finger Pad](https://mlsanity.com/paper/2507.07661/) (2025)

## Abstract (arXiv)

Human touch depends on the integration of shape, stiffness, and friction, yet existing tactile displays cannot render these cues together as continuously tunable, high-fidelity signals for intuitive perception. We present ArrayTac, a closed-loop piezoelectric tactile display that simultaneously renders these three dimensions with continuous tunability on a 4 by 4 actuator array. Each unit integrates a three-stage micro-lever amplifier with end-effector Hall-effect feedback, enabling up to 5 mm displacement, greater than 500 Hz array refresh, and 123 Hz closed-loop bandwidth. In psychophysical experiments, naive participants identified three-dimensional shapes and distinguished multiple stiffness and friction levels through touch alone without training. We further demonstrate image-to-touch rendering from an RGB image and remote palpation of a medical-grade breast tumor phantom over 1,000 km, in which all 11 naive participants correctly identified tumor number and type with sub-centimeter localization error. These results establish ArrayTac as a platform for multidimensional haptic rendering and interaction.