In a recent study published in the journal Science Advances, researchers leveraged crucial aspects of feline eyes, particularly their tapetum lucidum and vertically elongated pupils (VP), to develop a monocular artificial vision system capable of hardware-level object detection, recognition, and camouflage-breaking. While software-aided implementations of object recognition and tracking have been attempted, they require substantial energy and computation requirements, necessitating hardware-level innovations.
The present vision system uses a custom slit-like elliptical aperture (inspired by the asymmetric depth of field of cats’ VPs) to augment object focus and allow for an asymmetric depth of field, improving contrast between the target object and its background. An additional tapetum lucidum-inspired silicon photodiode array with patterned metal reflectors enhances low-light vision. Together, these advancements open the doors to a new generation of mobile robots that can detect, recognize, and track targets with significantly improved accuracy, even in dynamically changing environments with variable lighting conditions.
Background
The 21st century has witnessed unprecedented advancements in robotics and automation, resulting in the gradual influx of robotics across scientific, medical, industrial, and military applications. While software-based machine learning (ML) and artificial intelligence (AI) deployments have revolutionized robotic automation, hardware-level progress remains shackled by the limitations of conventional design and fabrication decisions.
An ideal example of the above is vision-based operation strategies. Conventional image-capturing devices (e.g., cameras) were optimized to record image data (e.g., light intensity, color, and object shape) but required user input to adjust aperture size and exposure duration to target objects focused under dynamically changing lighting. Modern robotics applications, particularly those used for surveillance, cannot be content with passive image data acquisition. Instead, they need to extract and analyze real-time image data and use this information to guide their subsequent motion.
“However, these tasks become substantially difficult under diverse environments and illumination conditions (e.g., indoor and outdoor and daytime and nighttime). This variability can severely affect the contrast between target objects and their backgrounds, mainly due to pixel saturation under bright conditions and low photocurrent in dark conditions. Objects often create indistinct boundaries with their backgrounds, posing detection and differentiation challenges.”
Software-based computer vision technologies, including high dynamic range (HDR), binocular vision-based camouflage-breaking, and AI-assisted post-processing, have partially addressed the hardware limitations of today’s robotics implementations. Unfortunately, these technologies require substantial computational and energetic (power/electricity) investment, increasing the size and running costs of resulting robotic systems. It is thus imperative for the future of robot automation that hardware capable of unassisted object identification, camouflage-breaking, and optimized performance under a wide range of lighting conditions is developed.
“…animals have adapted themselves to ecologically complex environments for their survival. As a result, distinctive vision systems optimized for their habitats have been developed through long-term evolution. These natural vision systems could offer potential solutions to tackle limitations of conventional artificial vision systems, in terms of depth of field (DoF), field of view (FoV), and optical aberrations.”
About the study
In the present study, researchers developed and tested an artificial vision system that mimics the feline eye. The system comprises two main components: a custom-made optical lens capable of varying apertures between elliptical, small shape, and full-opening circular and a novel hemispherical silicon photodiode array with patterned metal (silver) reflectors (HPA-AgR).
The photodiode array was fabricated by spin coating a silicon dioxide (SiO₂) wafer with a polyamic acid solution containing an ultrathin polyimide (PI) layer upon which a patterned reflector was superimposed using the wet-etching technique (100 nm Ag). The structured reflectors were designed to simulate the light-reflecting properties of the tapetum lucidum, enhancing light absorption under dim lighting conditions. The performance of the resulting photodiode was measured using a wide temperature (3100 K) halogen lamp, a probe station (image sensor array + semiconductor device analyzer), and a data acquisition (DAQ) board.
Monte Carlo-based ray tracing was used to evaluate the camouflage-breaking performance of the feline-inspired vision system versus conventional optical systems (circular pupil [CP]) against a variable lighting of 0-500 lumens.
Study findings
While monocular CP systems (including human eyes) struggle to differentiate between the target object and its background (pixel saturation) in extremely bright scenarios, the asymmetrical aperture design of feline eyes (feline VP) and, by extension, the current vision system can adjust focus between different (tangential and sagittal) planes thereby substantially offsetting light intensity and enabling camouflage breaking.
The design also allows for improved focus on objects at different distances, further reducing optical noise from background elements. Comparisons between the current VP-inspired and conventional CP-like systems highlight the latter’s lack of camouflage-breaking, especially in bright-light conditions. This is predominantly due to observed astigmatism between tangential and sagittal planes, which blurs the target and its background. In contrast, the VP system could easily distinguish between the target and the object irrespective of ambient light intensity. Furthermore, while ‘locked on’ a target, the vision system’s design blurs out the target’s background, reducing the amount of uninformative noise and thereby lowering the computational burden required for real-time analysis.
“Although computer vision and deep learning algorithms have substantially improved handling of noisy targets, the feline eye–inspired vision system provides intrinsic advantages originated from hardware. The feline eye–inspired artificial vision inherently induces background blurring and camouflage breaking, which can markedly reduce the computational burden.”
Similarly, while monocular CP systems achieve high camouflage-breaking performance in low-light conditions (wide-open pupils), they often suffer from low photocurrent in dark scenarios. Feline (and the current artificial) optics circumvent this limitation by not only fully dilating their VPs but also using their tapetum lucidum (or, in the artificial case, their metal reflectors) to reflect ambient light onto the pupil, further enhancing low-light target acquisition. Notably, comparisons between conventional CP optics and the current VP-inspired ones revealed that the novel system is 52-58% more efficient at photoabsorption than traditional technologies.
Despite these advances, the researchers noted one primary limitation of their system: its narrow field of view (FoV). Innovations in optic system movement (possibly inspired by the movements of cat heads) will be needed before these systems can be integrated into autonomous robotics.
Conclusions
The present study reports the development and validation of a novel, feline eye-inspired vision system. The system consists of a variable aperture lens and a metallic silicon photodiode array to achieve unprecedented, hardware-level object tracking and camouflage-breaking irrespective of the intensity of ambient light. While this vision system suffers from a low FoV, advancements in robotic movement may allow for its integration into autonomous robotics, allowing for a new generation of unmanned surveillance and tracking systems.
- Min Su Kim et al. Feline eye–inspired artificial vision for enhanced camouflage breaking under diverse light conditions. Sci. Adv.10, eadp2809 (2024), DOI – 10.1126/sciadv.adp2809, https://www.science.org/doi/10.1126/sciadv.adp2809
News
Scientists Discover Hidden Cause of Alzheimer’s Hiding in Plain Sight
Researchers found the PHGDH gene directly causes Alzheimer’s and discovered a drug-like molecule, NCT-503, that may help treat the disease early by targeting the gene’s hidden function. A recent study has revealed that a gene previously [...]
How Brain Cells Talk: Inside the Complex Language of the Human Mind
Introduction The human brain contains nearly 86 billion neurons, constantly exchanging messages like an immense social media network, but neurons do not work alone – glial cells, neurotransmitters, receptors, and other molecules form a vast [...]
Oxford study reveals how COVID-19 vaccines prevent severe illness
A landmark study by scientists at the University of Oxford, has unveiled crucial insights into the way that COVID-19 vaccines mitigate severe illness in those who have been vaccinated. Despite the global success of [...]
Annual blood test could detect cancer earlier and save lives
A single blood test, designed to pick up chemical signals indicative of the presence of many different types of cancer, could potentially thwart progression to advanced disease while the malignancy is still at an early [...]
How the FDA opens the door to risky chemicals in America’s food supply
Lining the shelves of American supermarkets are food products with chemicals linked to health concerns. To a great extent, the FDA allows food companies to determine for themselves whether their ingredients and additives are [...]
Superbug crisis could get worse, killing nearly 40 million people by 2050
The number of lives lost around the world due to infections that are resistant to the medications intended to treat them could increase nearly 70% by 2050, a new study projects, further showing the [...]
How Can Nanomaterials Be Programmed for Different Applications?
Nanomaterials are no longer just small—they are becoming smart. Across fields like medicine, electronics, energy, and materials science, researchers are now programming nanomaterials to behave in intentional, responsive ways. These advanced materials are designed [...]
Microplastics Are Invading Our Arteries, and It Could Be Increasing Your Risk of Stroke
Higher levels of micronanoplastics were found in carotid artery plaque, especially in people with stroke symptoms, suggesting a potential new risk factor. People with plaque buildup in the arteries of their neck have been [...]
Gene-editing therapy shows early success in fighting advanced gastrointestinal cancers
Researchers at the University of Minnesota have completed a first-in-human clinical trial testing a CRISPR/Cas9 gene-editing technique to help the immune system fight advanced gastrointestinal (GI) cancers. The results, recently published in The Lancet Oncology, show encouraging [...]
Engineered extracellular vesicles facilitate delivery of advanced medicines
Graphic abstract of the development of VEDIC and VFIC systems for high efficiency intracellular protein delivery in vitro and in vivo. Credit: Nature Communications (2025). DOI: 10.1038/s41467-025-59377-y. https://www.nature.com/articles/s41467-025-59377-y Researchers at Karolinska Institutet have developed a technique [...]
Brain-computer interface allows paralyzed users to customize their sense of touch
University of Pittsburgh School of Medicine scientists are one step closer to developing a brain-computer interface, or BCI, that allows people with tetraplegia to restore their lost sense of touch. While exploring a digitally [...]
Scientists Flip a Gut Virus “Kill Switch” – Expose a Hidden Threat in Antibiotic Treatment
Scientists have long known that bacteriophages, viruses that infect bacteria, live in our gut, but exactly what they do has remained elusive. Researchers developed a clever mouse model that can temporarily eliminate these phages [...]
Enhanced Antibacterial Polylactic Acid-Curcumin Nanofibers for Wound Dressing
Background Wound healing is a complex physiological process that can be compromised by infection and impaired tissue regeneration. Conventional dressings, typically made from natural fibers such as cotton or linen, offer limited functionality. Nanofiber [...]
Global Nanomaterial Regulation: A Country-by-Country Comparison
Nanomaterials are materials with at least one dimension smaller than 100 nanometres (about 100,000 times thinner than a human hair). Because of their tiny size, they have unique properties that can be useful in [...]
Pandemic Potential: Scientists Discover 3 Hotspots of Deadly Emerging Disease in the US
Virginia Tech researchers discovered six new rodent carriers of hantavirus and identified U.S. hotspots, highlighting the virus’s adaptability and the impact of climate and ecology on its spread. Hantavirus recently drew public attention following reports [...]
Studies detail high rates of long COVID among healthcare, dental workers
Researchers have estimated approximately 8% of Americas have ever experienced long COVID, or lasting symptoms, following an acute COVID-19 infection. Now two recent international studies suggest that the percentage is much higher among healthcare workers [...]
