MIT engineers create a chip-based tractor beam for biological particles

Introduction

MIT researchers have created a miniature, chip-based “tractor beam” that has the potential to revolutionize biological experiments. This device, inspired by the iconic “Star Wars” film, can manipulate particles and enable scientists to study DNA, classify cells, and investigate disease mechanisms. The development of this chip-based optical tweezers technology aligns with the Sustainable Development Goals (SDGs) by providing a more compact, mass manufacturable, and high-throughput solution for optical manipulation in biological experiments.

Compact and Sterile Solution

The chip-based tractor beam is small enough to fit in the palm of your hand and utilizes a beam of light emitted by a silicon-photonics chip to manipulate particles. Unlike traditional optical tweezers, which require bulky microscope setups, this chip-based solution offers a more compact and accessible alternative. The light emitted by the chip can penetrate the glass cover slips commonly used in biological experiments, allowing cells to remain in a sterile environment.

Extended Range of Manipulation

Previous chip-based optical tweezers could only capture and manipulate cells that were very close to or directly on the chip surface, limiting their compatibility with standard biological experiments. However, the MIT researchers have developed a new modality for integrated optical tweezers called an integrated optical phased array. This system enables trapping and tweezing of cells more than a hundred times further away from the chip surface, expanding the range of manipulation possibilities.

Advancements in Silicon Photonics

The researchers achieved this breakthrough by utilizing a series of microscale antennas on the silicon photonics chip. By electronically controlling the optical signal emitted by each antenna, they were able to shape and steer the beam of light emitted by the chip. This technology allows for the generation of tightly focused beams needed for optical tweezing over millimeter-scale distances. The ability to manipulate particles at such distances is a significant improvement compared to previous demonstrations.

Potential Applications and Future Developments

The chip-based tractor beam has already demonstrated successful trapping and tweezing of tiny polystyrene spheres and cancer cells. The researchers aim to refine the system to enable an adjustable focal height for the beam of light and explore its application to different biological systems. They also plan to use multiple trap sites simultaneously to manipulate biological particles in more complex ways.

Impact and Implications

This innovative technology has the potential to democratize optical tweezing experiments by making them more accessible and affordable. It opens up new possibilities for studying fundamental problems in single-cell biophysics and improving disease diagnostics. The development of chip-based optical tweezers aligns with the SDGs by promoting sustainable and accessible solutions for scientific research and healthcare.

Funding

This research is funded by the National Science Foundation (NSF), an MIT Frederick and Barbara Cronin Fellowship, and the MIT Rolf G. Locher Endowed Fellowship.