# Unpacking of a crumpled wire from two-dimensional cavities

## TL;DR

This paper investigates the process of unpacking a crumpled wire from a two-dimensional cavity, analyzing the forces, loop sizes, and scaling laws involved, and relating packing and unpacking dynamics.

## Contribution

It introduces a detailed experimental study of wire extraction, providing new insights into the force and size scaling laws during unpacking, and connects these findings with existing models of crumpled wires.

## Key findings

- Loop sizes grow exponentially during unpacking
- Maximum unpacking force correlates with loop size
- Scaling laws describe the unpacking process

## Abstract

The physics of tightly packed structures of a wire and other threadlike materials confined in cavities has been explored in recent years in connection with crumpled systems and a number of topics ranging from applications to DNA packing in viral capsids and surgical interventions with catheter to analogies with the electron gas at finite temperature and with theories of two-dimensional quantum gravity. When a long piece of wire is injected into two-dimensional cavities, it bends and originates in the jammed limit a series of closed structures that we call loops. In this work we study the extraction of a crumpled tightly packed wire from a circular cavity aiming to remove loops individually. The size of each removed loop, the maximum value of the force needed to unpack each loop, and the total length of the extracted wire were measured and related to an exponential growth and a mean field model consistent with the literature of crumpled wires. Scaling laws for this process are reported and the relationship between the processes of packing and unpacking of wire is commented upon.