Glass embedded with electric-field-driven electrodes removes dust from its surface without water or scrubbing, offering a durable, passive cleaning solution for solar panels and other exposed optical systems.
(Nanowerk Spotlight) Dust accumulation on solar panels can cut their energy output in half, even with as little as 5 milligrams of particulate matter per square centimeter. In arid and heavily polluted regions—such as parts of India, northern China, and the Middle East—this issue translates into persistent performance losses across large-scale solar farms. Manual cleaning remains the default solution, but it’s costly, water-intensive, and logistically difficult in hard-to-reach or environmentally sensitive areas.
Mechanical scrubbing poses risks to workers and to the delicate surfaces of photovoltaic modules, while the use of detergents introduces environmental concerns. The search for a scalable, non-contact cleaning method has led researchers to explore everything from bioinspired water-repellent coatings to autonomous robotic sweepers. However, most of these strategies break down under dry or dusty conditions, or require constant maintenance to remain effective.
One of the more promising directions involves using electric fields to manipulate surface particles. Technologies such as electrodynamic screens have shown potential for cleaning dust off solar panels without fluids or abrasion, and even saw deployment on Mars rovers. But these systems are hindered by a limited understanding of how particles actually begin to move and detach from surfaces under the influence of electric fields. The absence of a clear physical mechanism has left researchers guessing at optimal electrode configurations and power thresholds, and current systems still struggle with fine particles or nonuniform deposition patterns.
Against this backdrop, a team from Zhejiang University and collaborators has discovered a previously undocumented phenomenon in charged particle motion. Their experiments reveal that under an alternating electric field, surface particles not only move laterally but can also reverse direction or suddenly jump off the surface entirely—behaviors not predicted by conventional models. This insight led them to engineer a thin, transparent, self-cleaning glass capable of clearing nearly 98 percent of deposited particles in seconds, with no water, no chemicals, and minimal energy input. The research opens a path toward practical, passive self-cleaning systems for solar arrays, architectural glass, and other exposed surfaces that currently demand costly upkeep.
Abnormal transport and jump behaviors of charged particles and the design of transparent self-cleaning glass. (A) Schematic diagram of abnormal transport and jump behavior of charged particles in a non-uniform alternating electric field. (B) Photographs of abnormal transport and jump behavior of charged particles in a non-uniform alternating electric field. (C) Structure diagram of transparent self-cleaning glass. (D) Photograph of transparent self-cleaning glass. (E) The light transmittance of self-cleaning glass. Material a is an ordinary glass. Material b is a combination of glass and ITO electrode. Material c is a combination of glass and ITO electrode, and PET film. (F) The dynamic process of surface self-cleaning of self-cleaning glass. (G) The notable advantages of our self-cleaning glass compared with other existing self-cleaning devices driven by an electric field from five aspects. NG means that it is not given. (H) Applications of the coverable self-cleaning glass. (Image: Reprinted from DOI:10.1002/advs.202509404, CC BY) (click on image to enlarge)
The core of the research lies in the dynamic behavior of particles placed between electrodes on a glass surface. When exposed to a square-wave voltage of 5.5 kilovolts at 10 hertz, the particles—typically 100 micrometer silica spheres—moved laterally toward the positive electrode as expected. But shortly afterward, some reversed direction and moved away, a surprising outcome that conventional Coulomb-force-based models could not explain. When the voltage polarity switched, another phenomenon occurred: the particles abruptly jumped off the surface, traveling along the electric field lines in curved trajectories. These three behaviors—lateral movement, reverse lateral movement, and jumping—form the basis of a new understanding of surface particle transport in non-uniform, time-varying electric fields.
To make sense of these observations, the team constructed a detailed physical model that includes all significant forces acting on a particle at rest on a dielectric-covered electrode array. These include electrostatic attraction and repulsion (Coulomb force), polarization effects in non-uniform fields (dielectrophoretic force), van der Waals adhesion, gravity, air resistance, and friction. They simulated the electric field distribution using finite element methods and mapped out the combined force vectors at different positions on the surface. The result was a phase diagram showing how particles behave depending on their size and location relative to the electrodes, and how much electric field intensity is required to initiate movement or detachment.
Their analysis revealed distinct zones. Lateral transport tended to occur in the region between electrodes, where field gradients drive particles toward the nearest charged surface. Reverse transport, in contrast, occurred near the edges of electrodes, where sharp field gradients create a dielectrophoretic force strong enough to overpower the expected motion direction. Particle jumps were observed mainly at the centers of electrodes after polarity reversal, driven primarily by a sudden change in the direction of the Coulomb force. This detailed mapping allowed the researchers to predict exactly when and where particle movement would occur—and, crucially, where particles would remain trapped.
To eliminate these stagnation zones and improve uniform cleaning, the researchers modified the electrode geometry. Instead of using straight-edged electrodes, they designed a wavy pattern that disrupts the linear particle stagnation lines seen in rectangular configurations. This curvature helps dislodge particles that would otherwise remain pinned, both by providing escape paths along curved trajectories and by introducing more regions of locally intensified electric field. Experiments confirmed that the wavy electrode configuration left behind fewer residual particles and promoted a more even cleaning profile.
They also explored how the cleaning efficiency varied with particle material, size, and density. For a particle load of 97.79 grams per square meter, the system removed 97.5 percent of particles within ten seconds. The method worked across a range of particle types, from inorganic oxides like alumina and silica to organic polymers like PVC and PMMA. Heavier or more polarizable particles such as alumina benefited from stronger dielectrophoretic forces, while lighter, rougher particles like PVC were more resistant to removal due to increased adhesion and friction. Nevertheless, all materials tested showed over 94 percent cleaning efficiency at high dust loads.
To demonstrate real-world performance, the team applied the self-cleaning glass to a lab-scale photovoltaic panel. When contaminated with dust, the panel’s power output dropped by about 50 percent. After activating the cleaning system, output rose to within 94 percent of the clean-state baseline within four seconds. They repeated this test across a range of dust deposition densities and particle types, including real dust collected from photovoltaic installations in Inner Mongolia. Even under worst-case conditions, cleaning efficiencies exceeded 89 percent.
The dynamic process of surface self-cleaning of self-cleaning glass.
Beyond cleaning settled particles, the researchers found that the electric field also reduced new dust deposition. When the electric field was active, charged particles in the surrounding air were deflected before they could settle. The researchers called this a “particle shielding effect.” It reduced airborne particle deposition by nearly 90 percent, offering a continuous mitigation strategy during sandstorms or other dusty conditions.
The device’s transparent structure ensures compatibility with applications where light transmission is critical. The reduction in visible light transmittance was minimal, with the largest losses occurring in the infrared range. This makes the system suitable for use on solar panels, vehicle windshields, greenhouse roofs, or high-rise windows where visibility and efficiency must be preserved.
The simplicity of the design is also notable. The glass consists of common materials, and the fabrication process—etching ITO electrodes on a glass sheet and covering them with a PET film—is compatible with existing industrial techniques. The electrodes are driven by low-frequency signals requiring modest power, further supporting large-scale adoption.
By combining experimental observations, detailed modeling, and practical device design, this study lays the foundation for a new class of self-cleaning technologies that operate independently of weather conditions or water availability. The key contribution is not only the device itself but the fundamental insight into how charged particles move and detach from surfaces in time-varying electric fields. This understanding could inform future systems for particle manipulation, separation, and transport in clean energy, aerospace, and manufacturing contexts.
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