Engineers have introduced a solution to one of the persistently overlooked yet massive industrial problems: cell adhesion to walls in bioprocesses. Instead of aggressive enzymes, toxic coatings, or mechanical scraping, the new method uses electrochemically generated bubbles that—literally—"peel off" cells from the substrate whenever needed. This opens up possibilities for faster cultivation of CO₂-binding microalgae, more efficient production of biologic drugs, and cleaner, more predictable operations in the food, biopharmaceutical, and energy industries.

Why cells love to stick so much—and why it's expensive

Microalgae cells, as well as mammalian cells, naturally tend to adhere to the walls of reactors, plates, and membranes. In photobioreactors, this causes turbidity and shadowing of transparent tubes, leading to a slowdown in photosynthesis, a drop in growth rate, and forcing operators to shut down the system for cleaning. In the pharmaceutical industry, adherent cells are difficult and slow to detach with enzymes like trypsin, which increases consumable costs and generates liters of biological waste that needs to be disposed of. Similar problems plague biosensors, medical implants, membranes in bioprocesses, and production lines in the food industry, where biofilms force facilities into frequent "CIP/SIP" cleaning and sterilization cycles.

Custom-made electro-bubbles: how "on-demand" detachment works

The core idea is simple: when hydrogen and oxygen bubbles are created in water through electrolysis, they form precisely on the electrode surface. If we make this surface transparent, thin, and integrated with the inner wall of a reactor or culture plate, the bubbles will emerge exactly underneath the adhered cells. The moment a bubble detaches, a local micro-flow and shear stress are generated, breaking the adhesion bonds, and the cells are gently detached without chemical treatments. The key is precise control of current density: higher density means more nucleation sites and more frequent "micro-explosions" of bubbles, which more effectively sweeps away biofilms and cell deposits.

The problem with classic attempts was a byproduct: sodium chloride is present in physiological and algal media. At the anode, hypochlorite (bleach) can then be formed, which damages membranes and proteins. The engineering solution is to physically separate the anode from the working space with a membrane that only allows protons to pass (a proton-exchange membrane), while on the transparent, thin (e.g., gold) cathode along the wall, bubbles are generated without the formation of chlorine oxidants. This results in a clean, "chemically silent" mechanism that works in media for sensitive cells.

Transparent electrodes that don't spoil the light or the view

To maintain the transparency of photobioreactors and microscopic plates, an ultra-thin gold layer is deposited on the wall, which does not obstruct light. In photobioreactor tubes, such electrodes can be spirally wound or segmented along the flow, while in plates and "wells" for cell culture, they are integrated into the bottom. A modular solution is also possible: a robotic arm with a thin electrode "visits" each well and activates the bubbles only when detachment is needed, thereby reducing the load on electronics and energy consumption.

What this technology changes in photobioreactors

In closed photobioreactors, light is the currency of growth. Algal deposits on the walls reduce photon penetration and alter local optics, causing productivity to stagnate. When deposits are controlled by "bubble flushing" without chemicals, the frequency of reactor shutdowns is reduced. Instead of mandatory cleanings every ten to fifteen days, intervals can be extended, and cleaning operations become shorter and less aggressive. Furthermore, reactor design can once again become more compact: thinner tubes and a larger specific surface area mean a higher light-to-biomass ratio per volume, which is particularly important for cultivating algae for CO₂ capture or valorization.

Impact on energy balance and operational costs

Electrochemical bubble generation consumes energy, but this consumption must be compared with the gain in plant availability and growth. If the drop in productivity due to shadowing is avoided and "downtime" is reduced by a few percentage points, the overall effect on OPEX can be positive, even with continuous "micro-maintenance" with bubbles. Additionally, there are fewer consumable chemicals and lower costs for wastewater disposal from CIP.

From algae to therapies: applications in pharmaceuticals and biotechnology

In the production of biologic drugs and advanced therapies (including cell and gene therapies), the vitality and functionality of cells are crucial during every manipulation. Enzymatic detachment (e.g., trypsinization) can damage receptors, alter transcriptomic states, and prolong preparation cycles. Physical detachment with bubbles allows for faster processes, reduces the number of washing steps and the risk of contamination, and the cells remain highly viable. The method is "biologically agnostic": it does not rely on specific proteomes or adhesion molecules, but on local hydrodynamics and a controlled "micro-quake" that breaks adhesion.

Compatibility with existing equipment

The biggest advantage is its "plug-and-play" nature: transparent electrodes and PEM membranes can be integrated into standard formats—from T-flasks and multi-well plates to single-use bioreactor bags with transparent windows. In the scaling process, homogeneity is particularly important: by segmenting the electrodes and intelligently managing current pulses, a uniform bubble density is ensured over large areas.

What happens at the microscale: the bubble as a precision tool

When a bubble forms and detaches, surface energy is released, and a short-lived flow is created around the boundary layer. This generates shear stresses that are sufficient to detach the cells but too small to damage them. The geometry of the electrode, its roughness, and the wetting angle affect the size and frequency of bubble detachment. By adjusting the electrolyte and voltage, it is possible to achieve detection and removal of deposits as soon as they begin to form, before the biofilm stabilizes and strengthens with extracellular polymers.

Managing the risk of unwanted byproducts

To avoid the formation of hypochlorite, the anode is placed in a separate chamber behind a proton-exchange membrane. This separates the reaction zones: the cathode side along the reactor wall generates bubbles without oxidative species that would attack the cells or the medium. If necessary, the system can be operated in a pulsed mode (PWM), reducing heating and electrolytic gradients.

Industrial scenarios where the technology delivers immediate impact

• Photobioreactors for CO₂ capture and biorefineries: continuous "micro-flushing" of the walls, longer campaigns without cleaning, higher productivity with the same amount of light.


• Cell cultures in bioreactors and plates: faster passaging without enzymes, preserved phenotypic properties, less batch-to-batch variability.


• Biosensors and medical devices: delayed biofouling and longer operation in real conditions with minimal energy consumption.


• Food industry: less biofilm in pipes and tanks, easier CIP with lower chemical consumption.


• Membrane bioreactors and separation units: targeted "shaking off" of deposits without interrupting the main process.

Technological details: from materials to control electronics

Electrodes: ultra-thin layers of noble metals (e.g., gold) for biocompatibility and transparency; alternatively, conductive oxides (e.g., ITO) when additional optical transmittance is needed. Membranes: proton-exchange membranes (PEM) separate the anode chamber and prevent the diffusion of chlorine oxidants. Power supply: low-voltage sources with fast pulsing capability; current control is more precise than voltage control because it directly manages the bubble nucleation density.

Thermal management: due to low currents, local heating is limited, but for large surfaces, a cooling medium flow is introduced behind the electrodes. Sensors: optical or electrical monitoring of turbidity, reflection, and local impedance is used to automatically activate "bubble flushing" when deposits exceed a threshold.

Safety, regulatory landscape, and process qualification

In medical and pharmaceutical applications, replacing enzymatic steps with a physical procedure reduces the risks of residual reagents. Validation includes comparative tests of viability, membrane integrity, marker expression, and functional assays (e.g., cytotoxicity, differentiation). In data logging, the process is recorded as a combination of parameters: current density, pulse duration, number of cycles, and measured detachment performance. In the food industry, compatibility with CIP/SIP procedures and food-grade materials is crucial.

Economics: where the savings come from

The elimination or significant reduction of enzymes and aggressive agents brings direct savings on consumables. Indirect savings come from higher equipment availability, lower risk of contamination, and a reduced load on wastewater treatment plants. In photobioreactors, every additional percentage point of "uptime" is multiplied over time and volume, especially in campaigns where the goal is continuous CO₂ capture or cultivation for biodiesel, carotenoids, and other high-value compounds.

Limitations and challenges in scaling up

The biggest challenge is not the principle of detachment itself, but ensuring uniform action over large areas and complex geometries. It is necessary to "map" the current lines, prevent dead zones, and ensure that the bubbles do not "shadow" the light more than the removal of deposits benefits the process. The long-term stability of thin transparent electrodes and their mechanical resistance during CIP are also subjects of engineering optimization. In membrane systems, hydrodynamics must be coordinated so that the bubbles do not cause undesirable pressure fluctuations or foaming in the main flow.

Comparison with common methods

• Mechanical scraping: effective for coarse deposits, but abrasive, unsuitable for sensitive cultures, and often requires process shutdown.


• Enzymatic detachment: selective, but expensive and slow; can affect surface receptors and cell function.


• Coating treatments: reduce adhesion, but can be toxic, expensive, or incompatible with optics and sterilization.


• Electro-bubbles: activated on demand, act locally and quickly, without chemical residues, with high compatibility for different cells and substrates.

From "lab prototype" to field application

Laboratory prototypes have demonstrated the controlled detachment of algae, as well as extremely sensitive mammalian cells, with no drop in viability. Models have been developed that link current density, the number and size of bubbles, and the efficiency of cell removal. These models serve as design guides: an operating point is selected at which sufficient shear stress is achieved for the detection and removal of deposits, without compromising the integrity of the cells or the optical functionality of the transparent walls.

What it looks like in real plants

In a photobioreactor with transparent tubes, the operating sequence might look like this: turbidity and reflectance sensors periodically check the condition of the walls; when the signal exceeds a threshold, the controller activates short pulses on the segmented electrodes along the wall. The bubbles "sweep away" young deposits without interrupting the main flow. In cell culture plates, a robot brings an electrode above each well, activates detachment, and then aspiration and fresh medium complete the cycle without enzymatic treatment.

Environmental impact and sustainability

Fewer chemicals, less biological waste, and longer operation without cleaning mean a lower carbon footprint for the process. In plants for cultivating CO₂-capturing algae, this has a dual effect: the biomass itself binds carbon, and the optimized plant consumes less energy and resources for maintenance. In pharmaceutical processes, eliminating steps with enzymes and repeatedly generated washing solutions reduces the water and chemical "footprint".

What's next: integration with smart control and analytics

With advances in controllers and machine learning, predictive management of detachment is possible: models that learn from optical and electrical signals recognize the early stages of deposits and activate bubbles before the biofilm matures. Combined with real-time analytics, operators get an "autopilot" for clean walls and stable growth conditions.

Links for a deeper understanding of bubble physics

For readers who want to explore the bigger picture of the role of bubbles in electrolysis and on electrodes, it is useful to browse recent review articles and research on bubble nucleation, coalescence, and detachment, as well as strategies for accelerating bubble removal from surfaces. The role of "Marangoni" forces, superhydrophobic surfaces, and electrode microstructure confirms that the behavior of bubbles can be finely "conducted" to benefit the process through the design of surfaces and electrolytes.

Where to see the technology and how to request a demonstration

Industrial partners see the value most quickly through pilot integrations: a segmented transparent electrode installed in one loop of a photobioreactor or in one row of culture plates. After a month of monitoring metrics—time between cleanings, productivity per volume, chemical consumption, and cell viability—the return on investment is easily quantified. Technical teams can simultaneously conduct tests on electrode stability during CIP and validate the materials according to their own standards.

Answers to common technical questions

Will the bubbles disrupt the optical measurement line? The bubbles are short-lived and local; in pulsed mode, they can be synchronized with process phases that are not dependent on precise optical measurements. What about foaming? Foaming is minimal due to the local generation and rapid detachment of bubbles; if necessary, the gas flow at the exhaust is controlled. Material compatibility? Transparent electrodes and PEM membranes are chosen to withstand standard sterilization and CIP cycles; validation includes tests for extractables and mechanical resistance.

The role of the date and operational reality on October 17, 2025

As of October 17, 2025, the bioprocess industry is seeing accelerated adoption of passive and active methods against deposits; the trend is towards solutions that reduce chemical inputs and increase operational continuity. In this context, the electrochemical detachment of cells with bubbles fits into a broader shift towards "clean hydrodynamics" and electronics as a smart, finely tunable tool for in-line maintenance.

Technical recommendations for practical implementation

1. Risk assessment: map the zones most prone to deposits in the existing system.


2. Prototyping: install a transparent electrode on a limited surface (e.g., one tube loop, one plate) and calibrate the current density and pulse duration.


3. Sensor feedback: link activation to optical/electrical indicators of biofilm so that the system operates only "when needed."


4. Quality validation: on cells sensitive to shear stress, check viability, markers, and functionality after detachment.


5. Scaling up: segment the electrodes and stagger activation by zones to maintain uniformity in large volumes.

The bigger picture: from micro-bubbles to macro effects

At the level of microscopic milliseconds, a bubble changes the local flow and "snaps" adhesion bonds; at the plant level, maintenance schedules change, consumption of chemicals and wastewater decreases, and productivity no longer fluctuates due to shadowing and fouling. The combination of simple physics and thoughtful electrochemistry here becomes a tool that connects laboratory precision with industrial robustness, especially where cell health and process purity are unquestionable priorities.

Related entries and glossary

Photobioreactor, electrolysis, biofilm, proton-exchange membrane (PEM), enzymatic detachment (trypsin).