Vacuum Levitation

Researchers Achieve High Vacuum Levitation of Silica Nanoparticle, Paving the Way for Future Levitation Technologies

Researchers at ETH Zurich have successfully demonstrated the high vacuum levitation of a silica nanoparticle on a hybrid photonic-electric chip. This significant achievement, detailed in their latest study published in Nature Nanotechnology, represents a major leap forward in the field of nanotechnology and opens up new possibilities for future technological applications.

The breakthrough is the latest in a series of nanotechnology advancements, prompting some leading futurists to predict that developments in biotechnology, artificial intelligence, and nanobots will significantly impact humanity’s future in the coming years. 

“Levitation in vacuum has evolved into a versatile technique… [and] it holds great promise for advancing the study of quantum mechanics in the unexplored macroscopic regime,” study authors wrote. “However, most current levitation platforms are complex and bulky.” 

“Here we show levitation and motion control in high vacuum of a silica nanoparticle at the surface of a hybrid optical–electrostatic chip.” 

The ETH Zurich team’s hybrid chip consists of two layers: an upper photonic layer where the nanoparticle is trapped and detected and a lower electric layer with planar electrodes for feedback cooling. 

This setup allows for the precise detection of the nanoparticle’s motion by analyzing scattered light. This method achieves high signal-to-noise ratios without needing bulky, high-numerical-aperture lenses.

In practical terms, the photonic layer comprises four orthogonal cleaved single-mode optical fibers. These fibers form standing waves that create multiple trapping sites, efficiently canceling scattering forces and ensuring robust particle confinement. The lower layer utilizes electrodes for feedback cooling, stabilizing the particle’s motion in three dimensions and allowing for precise control.

This hybrid photonic-electric platform allows for robust levitation, precise position detection, and dynamic control of the nanoparticle in a vacuum without bulky optical equipment. 

This compact design could make the technology more practical for real-world applications, including portable devices and confined spaces such as cryostats.

The primary advantage of this new vacuum levitation method lies in its integration of optical and electrostatic components on a single chip, allowing for high precision and control over the nanoparticle’s motion. 

While this breakthrough primarily focuses on microscopic particles, the word “levitation” invokes intriguing questions about its implications for larger levitation technologies, including advanced propulsion systems. 

Microscopic vacuum levitation, such as the levitation of silica nanoparticles demonstrated in this recent study, fundamentally differs from the larger-scale levitation that people might associate with science fiction concepts like flying cars or “antigravity ships. 

At the microscopic level, the levitation is achieved using precise control of electromagnetic fields and laser cooling techniques within highly controlled environments, typically in vacuum conditions. These methods focus on counteracting the forces acting on tiny particles, allowing them to float or be suspended without physical contact.

In contrast, larger-scale levitation, such as that envisioned for exotic flying vehicles or spacecraft, would require overcoming the gravitational force acting on much larger masses. 

This would likely involve entirely different principles, such as magnetic levitation (maglev), which uses powerful magnets to lift and propel vehicles, or potential future technologies, which are currently theoretical. 

The engineering and energy requirements for such large-scale levitation are exponentially more significant, and the environmental conditions are more varied and challenging to control compared to a vacuum-sealed laboratory setup.

Ultimately, microscopic levitation is a well-studied and practical technique with existing technological applications. Large-scale levitation, like flying cars or “antigravity technologies, remains theoretical. 

Rather than attempting to achieve levitation, most experts working on next-generation propulsion systems are focusing on concepts like functional warp drives and hybrid plasma propulsion systems.

That said, the ability to levitate and control nanoparticles in high vacuum conditions could revolutionize several fields, including quantum computing, materials science, and precision sensing. 

Vacuum Levitation
a, The upper optical layer consists of two orthogonal pairs of cleaved single-mode optical fibres. One of the pairs (along y) creates a standing wave at λy = 1,550 nm, while the second pair (along x) creates a standing wave at λx = 1,064 nm. The distances between the fibres are dx = 80 μm and dy = 160 μm. A particle (black) is trapped at the intersection of both standing waves. The light scattered by the particle into the fibres, represented by the arrows, is used for displacement detection. The four fibres are positioned above a set of planar electrodes used to apply active feedback cooling to the charged particle via electric forces: right and left electrodes for feedback along x, top and bottom for feedback along y, and centre electrode for feedback along z. b, Picture of the levitation chip showing the planar electrodes, four optical fibres, fibre mounts close to the centre and wire bonds from the chip to the PCB at the corners. c, Optical fibre positioned into a mechanical mount fabricated via two-photon polymerization and used to align and hold the fibres in place. (Image Source: Dr. Bruno Melo, et al.)

The ETH Zurich researchers’ work offers a glimpse into a future where miniaturized, integrated levitation systems enable new experimental protocols and applications.

One of the most promising applications is in quantum mechanics. Precise control over nanoparticle motion can facilitate complex state preparation and readout, which is essential for quantum computing. 

Integrating photonics and nanophotonics with engineered electric potentials enhances control over particle motion, paving the way for scalable quantum systems.

Moreover, the ETH Zurich team’s approach could influence advancements in sensing technologies. By achieving high vacuum levitation, researchers can create more sensitive force and torque sensors, crucial in scientific experiments requiring precise measurements at microscopic scales. 

Despite the promising results, several challenges still need to be addressed. The stability and robustness of the levitation system in varied environments, the scalability of the technology, and the integration with other quantum systems are areas for future investigation. 

The ETH Zurich team is already planning to improve their platform further. Future studies will focus on enhancing detection sensitivity using refractive microlenses and integrating more sophisticated optical elements, such as fiber cavities. These advancements aim to achieve even greater control over particle motion and pave the way for complex state preparation and readout.

Ultimately, ETH Zurich’s breakthrough in high-vacuum levitation of silica nanoparticles on a chip marks a significant milestone in nanotechnology. Its potential applications in quantum computing, sensing technologies, and material science underscore the importance of continued research and development in this field. As technology evolves, it promises to open new horizons for scientific exploration and practical innovations.

“We envision our platform as the initial stepping stone towards the use of hybrid potentials for quantum experiments based on levitated particles, researchers concluded. 

Tim McMillan is a retired law enforcement executive, investigative reporter and co-founder of The Debrief. His writing typically focuses on defense, national security, the Intelligence Community and topics related to psychology. You can follow Tim on Twitter: @LtTimMcMillan.  Tim can be reached by email: or through encrypted email: