Related Experiment Video
Updated: May 28, 2025

07:57
Taking Advantage of Reduced Droplet-surface Interaction to Optimize Transport of Bioanalytes in Digital Microfluidics
Published on: November 10, 2014
7.8K
Optimal Navigation in Microfluidics via the Optimization of a Discrete Loss.
Petr Karnakov1, Lucas Amoudruz1, Petros Koumoutsakos1
1Harvard, Computational Science and Engineering Laboratory, John A. Paulson School of Engineering and Applied Sciences, Cambridge, Massachusetts 02138, USA.
Physical Review Letters
|February 14, 2025
Summary
We developed a new closed-loop control method for microscopic devices in fluids. This method, optimizing a discrete loss (ODIL), is faster and more robust than reinforcement learning for complex navigation tasks.
Area of Science:
- Robotics and fluid dynamics
- Micro-robotics and autonomous systems
Background:
- Navigating microscopic devices in fluid environments presents significant challenges due to complex microdevice-flow interactions.
- Applications include targeted drug delivery and environmental monitoring, requiring precise control and path planning.
Purpose of the Study:
- To introduce a novel closed-loop control method for optimizing the path planning and control of microscopic devices.
- To address the limitations of existing methods in high-dimensional and complex flow environments.
Main Methods:
- Development of a closed-loop control method that optimizes a discrete loss (ODIL).
- Evaluation of ODIL's performance against reinforcement learning in terms of speed, robustness, and scalability.
Main Results:
- ODIL demonstrates superior robustness compared to reinforcement learning.
- ODIL achieves speeds up to three orders of magnitude faster than reinforcement learning.
- The method excels in high-dimensional action and state spaces, crucial for complex micro-robot navigation.
Conclusions:
- ODIL offers a powerful and efficient solution for controlling microscopic devices in complex fluid environments.
- This method significantly advances the capabilities for micro-robotics applications such as targeted drug delivery.

