Robotic Dexterous Manipulation via Anisotropic Friction Modulation using Passive Rollers

TL;DR

This paper introduces a robotic fingertip with passive rollers that can modulate contact friction and constraint directions, enabling versatile dexterous manipulation strategies.

Contribution

The design of passive rollers with selective braking and reorientation provides a mechanically simple method for friction modulation in robotic fingertips.

Findings

Enables sliding and pivoting within the grasp

Supports robust adaptation to uncertain contacts

Facilitates multi-object and multi-part manipulation

Abstract

Controlling friction at the fingertip is fundamental to dexterous manipulation, yet remains difficult to realize in robotic hands. We present the design and analysis of a robotic fingertip equipped with passive rollers that can be selectively braked or pivoted to modulate contact friction and constraint directions. When unbraked, the rollers permit unconstrained sliding of the contact point along the rolling direction; when braked, they resist motion like a conventional fingertip. The rollers are mounted on a pivoting mechanism, allowing reorientation of the constraint frame to accommodate different manipulation tasks. We develop a constraint-based model of the fingertip integrated into a parallel-jaw gripper and analyze its ability to support diverse manipulation strategies. Experiments show that the proposed design enables a wide range of dexterous actions that are conventionally challenging for robotic grippers, including sliding and pivoting within the grasp, robust adaptation to uncertain contacts, multi-object or multi-part manipulation, and interactions requiring asymmetric friction across fingers. These results demonstrate the versatility of passive roller fingertips as a low-complexity, mechanically efficient approach to friction modulation, advancing the development of more adaptable and robust robotic manipulation.