# Force induced formation of twisted chiral ribbons

## TL;DR

This paper investigates how applying a stretching force to colloidal membranes induces the formation of twisted chiral ribbons, combining experiments and theory to understand their shape and mechanical response.

## Contribution

It introduces a new effective theory that explains the formation and shape of force-induced twisted chiral ribbons, integrating membrane bending energy and liquid crystalline properties.

## Key findings

- Force transforms membranes into twisted ribbons with specific handedness.
- Theoretical model accurately predicts force-extension behavior and ribbon shape.
- Experimental measurements validate the model's predictions.

## Abstract

We study the emergence of helical structures subjected to a stretching force, demonstrating that the force transforms disk-shaped colloidal membranes into twisted chiral ribbons of predetermined handedness. Using an experimental technique that enforces torque-free boundary conditions we simultaneously measure the force-extension curve and quantify the shape of emergent ribbons. An effective theory that accounts for the membrane bending energy and uses geometric properties of the edge to model the internal liquid crystalline degrees of freedom explains both the measured force-extension curve and shape of the twisted ribbons in response to an applied force.