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Just a few years ago, sperm preparation for assisted reproductive technology (ART) programs was perceived as a purely technical stage that had almost no impact on the final result. However, modern research shows: the quality of the selected sperm can play a critical role in fertilization, embryo development, and even its implantation.
The problem is that standard ejaculate processing methods do not always allow for the separation of sperm with damaged DNA or increased levels of oxidative stress. As a result, even with “normal” semen analysis parameters, the effectiveness of IVF programs may remain lower than expected.
That is why, in recent years, microfluidic technologies — in particular, so-called sperm chips — have been attracting more and more attention. They allow for the replication of natural sperm selection and the acquisition of a cell population with superior functional characteristics.
What are microfluidic technologies?
Modern reproductive medicine is increasingly moving toward precision and delicacy. While the main focus used to be on “processing” cells, today it is on creating conditions in which they can manifest their natural properties.
Microfluidic selection is a system of microchannels in which controlled fluid movement with cells occurs. Under such conditions:
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mechanical load is reduced,
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oxidative stress is lowered,
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cells behave more similarly to natural conditions.
Sperm chips are based on exactly this principle.
How does Microfluidic Sperm Sorting work?
The microfluidic sperm sorting method allows for the selection of sperm not by appearance, but by their behavior.
A system of chambers and channels is created in the chip:
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the ejaculate is introduced into the starting chamber,
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a clean medium is placed in the final chamber.
Only the most motile and functionally complete sperm are able to complete this journey.
This is important because:
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motility is directly linked to cell functionality,
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sperm with damaged DNA more often have poorer migratory ability.
Operating principle of a sperm chip:
1 – the sperm sample is introduced into the inlet port of the device, which is connected to the lower sample chamber.
2 – the lower chamber is separated from the upper collection chamber by a microporous membrane. Culture medium is added to the surface of this membrane.
3 – during incubation, the most progressively motile sperm pass through the membrane pores into the fresh medium. As a result, a fraction of motile sperm suitable for use (specifically for ICSI) is obtained from the outlet port.
What types of sperm chips are there?
Despite a common operating principle, different types of sperm chips differ in their cell selection mechanisms. In clinical practice, several types of microfluidic systems exist, but they all work on a shared principle — selecting sperm based on their functionality rather than just external characteristics.
They can be broadly categorized into several approaches:
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systems where sperm migrate independently through microchannels — the most physiological option;
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chips with microlabyrinths and artificial obstacles that filter out lower-quality cells;
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systems with controlled fluid flow that allow for the selection of the most motile cells;
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gradient approaches that mimic natural signals (e.g., movement against the flow or reaction to chemical factors).
All these technologies share one goal — to bring laboratory selection closer to the natural process that occurs in the body.
How effective is it: figures and facts
Microfluidic technologies are being actively researched — and data is already available to evaluate their effectiveness.
According to modern research:
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microfluidic selection reduces the level of DNA fragmentation in sperm by 15% compared to the classic method of sperm preparation via density gradient centrifugation [1],
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increases the proportion of progressively motile sperm [2],
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contributes to an increase in the clinical pregnancy rate by 5% (compared to standard selection methods) [3].
Important note: these indicators are not universal and may vary depending on the specific clinical case.
When is microfluidic sperm selection recommended?
The greatest effect is observed in cases of:
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increased sperm DNA fragmentation,
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idiopathic infertility,
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repeated IVF program failures.
What are the limitations for using sperm chips?
Microfluidic sperm selection is not recommended for patients with severe male factor infertility, as it will be difficult to obtain a sufficient number of sperm. Use may be limited for pre-cryopreserved sperm samples.
Are there “oocyte chips”?
Yes, but their role is different. While the key for sperm is selection, for oocytes it is creating an optimal environment. If selection is crucial for sperm, then environmental conditions are crucial for eggs.
Microfluidic technologies for oocytes
Today, such systems are being actively developed and are already showing promising results.
Cultivation and maturation (IVM)
In microfluidic systems:
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the composition of the medium is stabilized,
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a constant exchange of nutrients is ensured.
According to experimental research:
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the oocyte maturation rate can increase by 10–20%,
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the quality of cytoplasmic maturation improves.
Embryo development
In microfluidic platforms:
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embryos develop in a more stable environment,
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the influence of external factors is reduced.
Some studies show:
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an increase in the rate of reaching the blastocyst stage by 5–15%,
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more synchronous embryo development.
Less stress for cells
Microfluidic systems allow for:
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reducing the number of manipulations,
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avoiding fluctuations in temperature and pH,
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working in a closed environment.
This is especially important for cells that are highly sensitive to changes in conditions.
What does this mean for patients?
The use of microfluidic technologies is not a “guarantee of pregnancy.”
It is a modern tool that can provide an additional advantage where it is truly needed.
It is a modern tool that can provide an additional advantage where it is truly needed.
In clinical practice, they are most often used:
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for male factor infertility,
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for increased DNA fragmentation,
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after unsuccessful IVF attempts.
The main value of these technologies lies in personalization and ease of use.
Sometimes, it is precisely a small improvement in cell quality that becomes the factor that changes the outcome.
Conclusions
Microfluidic sperm chips are not a universal solution and do not completely replace traditional sperm preparation methods. However, they offer a new approach to sperm selection — more delicate, physiological, and focused on quality rather than just quantity.
In clinical practice, this can be of particular importance for couples with repeated IVF failures, increased sperm DNA fragmentation, or unexplained causes of infertility. At the same time, the choice of method should always remain individual and be based on the characteristics of the specific sample.
Modern embryology is gradually moving from “material processing” to more precise and careful cell selection. Today, success in ART programs increasingly depends on more than just one “decisive factor.” Instead, it is built from precise decisions that together increase the likelihood of a result.
List of sources used
- Huong, Do Thuy et al. “Comparative Efficacy of Microfluidics and Density Gradient Centrifugation for Sperm Preparation in IVF: A Randomized Controlled Trial.” JBRA assisted reproduction, 10.5935/1518-0557.20250190. 2 Feb. 2026, doi:10.5935/1518-0557.20250190
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Gisbert Iranzo, A., Cano-Extremera, M., Hervás, I., Falquet Guillem, M., Gil Juliá, M., Navarro-Gomezlechon, A., Pacheco-Rendón, R. M., & Garrido, N. (2025). Sperm Selection Using Microfluidic Techniques Significantly Decreases Sperm DNA Fragmentation (SDF), Enhancing Reproductive Outcomes: A Systematic Review and Meta-Analysis. Biology, 14(7), 792. https://doi.org/10.3390/
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Yetkinel, S., Kilicdag, E. B., Aytac, P. C., Haydardedeoglu, B., Simsek, E., & Cok, T. (2019). Effects of the microfluidic chip technique in sperm selection for intracytoplasmic sperm injection for unexplained infertility: a prospective, randomized controlled trial. Journal of assisted reproduction and genetics, 36(3), 403–409. https://doi.org/10.1007/
s10815-018-1375-2