# Arrays of individually controllable optical tweezers based on 3D-printed microlens arrays

## TL;DR

This paper introduces a new optical tweezer platform that combines 3D-printed microlens arrays with spatial light modulation, enabling dynamic, scalable, and customizable manipulation of microscopic particles.

## Contribution

It presents a novel combination of rapid 3D printing and digital modulation for flexible, stable, and scalable optical tweezer arrays with real-time control.

## Key findings

- Successful fabrication of a 97-lens microlens array with different packing geometries
- Demonstration of real-time, individual control of each tweezer spot using DMD
- Wide tunability of tweezer properties through simple parameter adjustments

## Abstract

We present a novel platform of optical tweezers which combines rapid prototyping of user-definable microlens arrays with spatial light modulation (SLM) for dynamical control of each associated tweezer spot. Applying femtosecond direct laser writing, we manufacture a microlens array of 97 lenslets exhibiting quadratic and hexagonal packing and a transition region between the two. We use a digital micromirror device (DMD) to adapt the light field illuminating the individual lenslets and present a detailed characterization of the full optical system. In an unprecedented fashion, this novel platform combines the stability given by prefabricated solid optical elements, fast reengineering by rapid optical prototyping, DMD-based real-time control of each focal spot, and extensive scalability of the tweezer pattern. The accessible tweezer properties are adaptable within a wide range of parameters in a straightforward way.