University of Michigan · Robotics

Xili Yi

I am a 5th-year PhD candidate in robotics working on contact-rich manipulation. My research combines physics, sensing, and learning to give robots a deeper understanding of how objects behave through friction, deformation, and vibration. I develop methods and sensing modalities that reveal the structure of contact—so robots can predict, control, and generalize their interactions more reliably in the real world.

Contact-rich manipulation Multimodal perception (tactile, vibration, audio) Physics-based modeling & learning

I expect to graduate in Spring/Summer 2026 and am open to research and engineering opportunities in robotics.

Email Google Scholar LinkedIn

Fingertip micro-vibration reconfiguration in hand

VIB2MOVE micro-vibration regrasp

Parallel-jaw gripper repositioning objects with vibration.

Dual Limit Surfaces

Frictional model and planner that keeps top contact locked in place.

Dual Limit Surfaces in general cases

Slippage-free sliding on horizontal/inclined surfaces.

VIB2MOVE: In-hand Object Reconfiguration via Fingertip Micro-Vibrations

X. Yi, N. Fazeli

Robotics: Science and Systems (RSS) 2025

VIB2MOVE introduces a fingertip actuator that modulates friction with micro-vibrations, a sliding dynamics model, and a planner that synchronizes end-effector motion with vibration phases. The approach reliably repositions planar objects using a simple parallel gripper, achieving sub-centimeter accuracy across a range of shapes.

Paper Project Page

VA2CONTACT: Visual-auditory Extrinsic Contact Estimation

X. Yi, J. Lee, N. Fazeli

(submitted)

VA2CONTACT fuses global visual context with local cues from active audio excitation to infer where grasped objects touch the environment. The system leverages differentiable acoustic rendering, an attention-based fusion network, and a contact reasoning head that transfers from simulation to real hardware without additional finetuning.

Paper Project Page

Dual limit surfaces sliding path comparison

Dual asymmetric limit surfaces and their applications to planar manipulation

X. Yi, A. Dang, N. Fazeli

Autonomous Robots

We extended Precise Object Sliding with Top Contact via Asymmetric Dual Limit Surfaces to more general cases including inclined surfaces.

Paper Project Page Code

Precise Object Sliding with Top Contact via Asymmetric Dual Limit Surfaces

X. Yi, N. Fazeli

Robotics: Science and Systems (RSS) 2023

We model the frictional interactions at the top gripper-object interface and bottom support plane simultaneously via asymmetric Dual Limit Surfaces, then plan twists that keep the gripper stuck while the object slips to its goal. The planner avoids orientation drift and empirically cuts final pose error by 90% compared to linear paths.

Paper Project Page Code

Torsional Stiffness Improvement of a Soft Pneumatic Finger Using Embedded Skeleton

A. Lotfiani, H. Zhao, Z. Shao, X. Yi

Journal of Mechanisms and Robotics 2020

We enhance the torsional stiffness of soft robotic actuators without sacrificing their compliance by embedding tunable internal reinforcement. Our design preserves flexibility in bending and extension while providing significantly greater resistance to twist, enabling more stable, controllable, and load-capable soft robots.

Paper link

2025

Presented Vib2Move at RSS 2025, showing that with fingertip micro-vibrations that modulate friction in-hand, we can enable millimeter-level object reconfiguration with a parallel jaw gripper in free space.

2024

Published Dual asymmetric limit surfaces and their applications to planar manipulation at Autonomous Robots, extended Dual Limit Surfaces model to more general cases.

2023

Presented Dual Limit Surfaces at RSS 2023, showing that asymmetric friction modeling and constrained planners enable precise top-contact sliding with 90% lower orientation error than naive path planners.

Let's collaborate

I'm always excited to chat about tactile perception, contact-rich planning, and experimental robotics. Reach me at yixili@umich.edu.