Engineers Look to Fish for Microplastics Filter Design

Microplastic filters designed from fish gills
are found to be over 99% efficient,
surpassing present plastic filter technologies

Engineers Look to Fish for Microplastics Filter Design

by Dr. Sarah Buckland-Reynolds

Fish are often admired for their beauty and graceful glides through water. Indeed, fish have served as models for numerous biomimetic innovations over the years – from drag‑reducing surfaces for swimsuits and aircraft coatings, aerodynamic car design, to even informing algorithms for swarm robotics and traffic flow optimization.

However, new scientific innovation has uncovered yet another amazing engineering template based on fish design. The latest invention targets one of the major global environmental issues: reducing microplastics. Researchers Hamman et al from the University of Bonn published this innovation breakthrough in Nature npj Emerging Contaminants journal in 2025. They report the astounding finding that their Fish-Inspired Filter (FIF) has an efficiency of up to 99.6% in removing microplastics when used in washing machines. This bio-inspired innovation has immense environmental protection implications, as washing machines are ranked as one of the world’s major sources of microplastics, releasing between 10 and 120 grams of microplastic fibres per person per year.

This remarkable efficiency invites reflection not only on biomimicry but also on the deeper question of design. Evolutionary explanations attribute such systems to millions of years of trial-and-error adaptation. Intelligent Design, however, recognizes them as purposeful, irreducible, and optimal systems that testify to a transcendent Designer.

Biomimicry: Learning from Fish

Ram-feeding fishes such as anchovies, pilchards, and mackerel employ a semi-cross-flow filtration system. Their gill arches form a cone-shaped geometry that tapers toward the oesophagus, enabling particles to roll along a mesh-like structure rather than clogging it. In fish, gill rakers and their associated denticles or surface structures function as a ‘mesh-like’ structure, often bearing denticles (tiny tooth‑like projections) or mucus layers that create a sieve‑like surface. This intercepts particles while allowing water to pass.

This functionality was recognized by scientists, leading to the creation of the innovation of the microplastic filter using the special gill design from these types of fish. The rolling motion along the cone-shaped gill forms a crucial component that revolutionized the design of these new microplastic filters. Instead of particles slamming into a flat barrier, they are guided toward the gullet, where they accumulate before being swallowed. The process mimics the funnel shape, which in the fish, enables plankton to efficiently roll towards the gullet. In this section, the plankton is stored until the fish would swallow, which enables the system to be emptied and cleaned. By replicating this geometry, engineers created a washing machine filter that not only captures microplastics but also resists clogging through periodic self-cleaning.

The Limitations of Evolutionary Explanations

Evolutionary biology frames these systems as the product of gradual adaptation. Yet, when examining the complexity and efficiency of the system, there are several processes involved for which evolution fails to account. Among these include:

1. Irreducible Complexity

These features in fish gills depends on multiple interdependent parameters: cone geometry, angle of attack, gill raker size and periodic cleaning. Applied to the Fish-Inspired Filter (FiF) design Hamman et al also admit to the multiple specifications required for the FIF to be functional. In their words:

“Filter performance depends on specific parameter combinations and can thus be tailored to a wide range of potential applications”.

For functionality, the semi-cross-flow filtration system jointly integrates several principles of physics, including fluid dynamics, rolling motion, and self-cleaning. The Nature article describes it as “unique in its combination of (i) a cone-shaped filter element… (ii) a filter housing with adapted inflow… and (iii) an adjustable periodic cleaning mechanism” (Hamann et al., 2025). Such interdependence suggests irreducible complexity, as missing any of these parameters systems would not function if any part were missing. Evolutionary theory struggles to explain the sudden emergence of such novelty without foresight. Incomplete versions would not confer survival advantage, therefore a stepwise and gradual formation of these traits is a less reasonable inference than intelligent design.

2. Efficiency Beyond Trial-and-Error

The FIF’s efficiency is noted by the authors as retaining “99.6 ± 0.8% of MP fibres in the lab experiments”. Evolutionary explanations rely on random mutations filtered by natural selection. Yet the gill arch system demonstrates optimal efficiency. How would a sequence of chance mutations and selections produce a mechanism with such high efficiency that surpasses many human-engineered solutions? If human-engineered solutions requires intelligent design, why shouldn’t the same logic be held for fish gills that possess such high efficiency?

The Superiority of Intelligent Design Perspective

The Intelligent Design framework offers a more coherent explanation, as the FiF reflects engineering principles: cone geometry, mesh filtration, rolling dynamics, and self-cleaning. These are hallmarks of intentional design. Engineers did not invent these principles; they discovered them in nature. As Hamann et al admit: “Our findings highlight the potential of bio-inspired filtration mechanisms for engineering applications such as washing machines requiring high efficiency and modular design” (Hamann et al., 2025).

Holding an intelligent design perspective further propels innovations such as described by Hamman et al. An Intelligent Design predicts that studying biological systems would yield engineering insights, while an evolutionary perspective has no basis to assume finely tuned engineering. Biomimicry consistently validates this, with the FiF just being yet another example of predictive success.

Fearfully and Wonderfully Made

The Fish-Inspired Filter presents yet another powerful affirmation that creation testifies to divine wisdom. As Psalm 104:24 declares: “O Lord, how manifold are your works! In wisdom have you made them all; the earth is full of your creatures.”

Romans 1:20 reminds us: “For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived… in the things that have been made.” The FiF’s efficiency is a tangible testimony to these attributes.

Evolutionary explanations falter when confronted with the amazing features embedded in fish gills: irreducible complexity, efficiency, novelty, and teleology. Intelligent Design provides a coherent framework that recognizes these systems as purposeful, engineered solutions.

In addition to its amazing design, the application of this innovation also aligns with both divine mandates of stewardship and responsible dominion. The biomimicry of fish gills in a washing machine filter not only solves ecological problems but also points us toward the greater reality: the world is filled with testimonies of intelligent design, inviting us to worship the One who made them.

Dr. Sarah Buckland-Reynolds is a Christian, Jamaican, Environmental Science researcher, and journal associate editor. She holds the degree of Doctor of Philosophy in Geography from the University of the West Indies (UWI), Mona with high commendation, and a postgraduate specialization in Geomatics at the Universidad del Valle, Cali, Colombia. The quality of her research activity in Environmental Science has been recognized by various awards including the 2024 Editor’s Award from the American Meteorological Society for her reviewing service in the Weather, Climate and Society Journal, the 2023 L’Oreal/UNESCO Women in Science Caribbean Award, the 2023 ICETEX International Experts Exchange Award for study in Colombia. and with her PhD research in drought management also being shortlisted in the top 10 globally for the 2023 Allianz Climate Risk Award by Munich Re Insurance, Germany. Motivated by her faith in God and zeal to positively influence society, Dr. Buckland-Reynolds is also the founder and Principal Director of Chosen to G.L.O.W. Ministries, a Jamaican charitable organization which seeks to amplify the Christian voice in the public sphere and equip more youths to know how to defend their faith.