{"type": "FeatureCollection", "features": [{"id": "PMC11468586", "type": "Feature", "geometry": null, "properties": {"updated": "2026-05-24T16:27:06Z", "type": "Journal Article", "created": "2021-09-08", "title": "Wafer\u2010Scale Functional Metasurfaces for Mid\u2010Infrared Photonics and Biosensing", "description": "Abstract

Metasurfaces have emerged as a breakthrough platform for manipulating light at the nanoscale and enabling on\uffe2\uff80\uff90demand optical functionalities for next\uffe2\uff80\uff90generation biosensing, imaging, and light\uffe2\uff80\uff90generating photonic devices. However, translating this technology to practical applications requires low\uffe2\uff80\uff90cost and high\uffe2\uff80\uff90throughput fabrication methods. Due to the limited choice of materials with suitable optical properties, it is particularly challenging to produce metasurfaces for the technologically relevant mid\uffe2\uff80\uff90infrared spectral range. These constraints are overcome by realizing functional metasurfaces on almost completely transparent free\uffe2\uff80\uff90standing metal\uffe2\uff80\uff90oxide membranes. A versatile nanofabrication process is developed and implemented for highly efficient dielectric and plasmonic mid\uffe2\uff80\uff90infrared metasurfaces with wafer\uffe2\uff80\uff90scale and complementary metal\uffe2\uff80\uff93oxide\uffe2\uff80\uff93semiconductor (CMOS)\uffe2\uff80\uff90compatible manufacturing techniques. The advantages of this method are revealed by demonstrating highly uniform and functional metasurfaces, including high\uffe2\uff80\uff90Q structures enabling fine spectral selectivity, large\uffe2\uff80\uff90area metalenses\uffc2\uffa0with\uffc2\uffa0diffraction\uffe2\uff80\uff90limited focusing capabilities, and birefringent metasurfaces providing polarization control at record\uffe2\uff80\uff90high conversion efficiencies.\uffc2\uffa0 Aluminum plasmonic devices and their integration into microfluidics for real\uffe2\uff80\uff90time and label\uffe2\uff80\uff90free mid\uffe2\uff80\uff90infrared biosensing of proteins and lipid vesicles are further demonstrated. The versatility of this approach and its compatibility with mass\uffe2\uff80\uff90production processes bring infrared metasurfaces markedly closer to commercial applications, such as thermal imaging, spectroscopy, and biosensing.Insights into the fascinating molecular world of biological processes are crucial for understanding diseases, developing diagnostics, and effective therapeutics. These processes are complex as they involve interactions between four major classes of biomolecules, i.e., proteins, nucleic acids, carbohydrates, and lipids, which makes it important to be able to discriminate between all these different biomolecular species. In this work, a deep learning\uffe2\uff80\uff90augmented, chemically\uffe2\uff80\uff90specific nanoplasmonic technique that enables such a feat in a label\uffe2\uff80\uff90free manner to not disrupt native processes is presented. The method uses a highly sensitive multiresonant plasmonic metasurface in a microfluidic device, which enhances infrared absorption across a broadband mid\uffe2\uff80\uff90IR spectrum and in water, despite its strongly overlapping absorption bands. The real\uffe2\uff80\uff90time format of the optofluidic method enables the collection of a vast amount of spectrotemporal data, which allows the construction of a deep neural network to discriminate accurately between all major classes of biomolecules. The capabilities of the new method are demonstrated by monitoring of a multistep bioassay containing sucrose\uffe2\uff80\uff90 and nucleotides\uffe2\uff80\uff90loaded liposomes interacting with a small, lipid membrane\uffe2\uff80\uff90perforating peptide. It is envisioned that the presented technology will impact the fields of biology, bioanalytics, and pharmacology from fundamental research and disease diagnostics to drug development.Metasurfaces have emerged as a breakthrough platform for manipulating light at the nanoscale and enabling on\uffe2\uff80\uff90demand optical functionalities for next\uffe2\uff80\uff90generation biosensing, imaging, and light\uffe2\uff80\uff90generating photonic devices. However, translating this technology to practical applications requires low\uffe2\uff80\uff90cost and high\uffe2\uff80\uff90throughput fabrication methods. Due to the limited choice of materials with suitable optical properties, it is particularly challenging to produce metasurfaces for the technologically relevant mid\uffe2\uff80\uff90infrared spectral range. These constraints are overcome by realizing functional metasurfaces on almost completely transparent free\uffe2\uff80\uff90standing metal\uffe2\uff80\uff90oxide membranes. A versatile nanofabrication process is developed and implemented for highly efficient dielectric and plasmonic mid\uffe2\uff80\uff90infrared metasurfaces with wafer\uffe2\uff80\uff90scale and complementary metal\uffe2\uff80\uff93oxide\uffe2\uff80\uff93semiconductor (CMOS)\uffe2\uff80\uff90compatible manufacturing techniques. The advantages of this method are revealed by demonstrating highly uniform and functional metasurfaces, including high\uffe2\uff80\uff90Q structures enabling fine spectral selectivity, large\uffe2\uff80\uff90area metalenses\uffc2\uffa0with\uffc2\uffa0diffraction\uffe2\uff80\uff90limited focusing capabilities, and birefringent metasurfaces providing polarization control at record\uffe2\uff80\uff90high conversion efficiencies.\uffc2\uffa0 Aluminum plasmonic devices and their integration into microfluidics for real\uffe2\uff80\uff90time and label\uffe2\uff80\uff90free mid\uffe2\uff80\uff90infrared biosensing of proteins and lipid vesicles are further demonstrated. The versatility of this approach and its compatibility with mass\uffe2\uff80\uff90production processes bring infrared metasurfaces markedly closer to commercial applications, such as thermal imaging, spectroscopy, and biosensing.Insights into the fascinating molecular world of biological processes are crucial for understanding diseases, developing diagnostics, and effective therapeutics. These processes are complex as they involve interactions between four major classes of biomolecules, i.e., proteins, nucleic acids, carbohydrates, and lipids, which makes it important to be able to discriminate between all these different biomolecular species. In this work, a deep learning\uffe2\uff80\uff90augmented, chemically\uffe2\uff80\uff90specific nanoplasmonic technique that enables such a feat in a label\uffe2\uff80\uff90free manner to not disrupt native processes is presented. The method uses a highly sensitive multiresonant plasmonic metasurface in a microfluidic device, which enhances infrared absorption across a broadband mid\uffe2\uff80\uff90IR spectrum and in water, despite its strongly overlapping absorption bands. The real\uffe2\uff80\uff90time format of the optofluidic method enables the collection of a vast amount of spectrotemporal data, which allows the construction of a deep neural network to discriminate accurately between all major classes of biomolecules. The capabilities of the new method are demonstrated by monitoring of a multistep bioassay containing sucrose\uffe2\uff80\uff90 and nucleotides\uffe2\uff80\uff90loaded liposomes interacting with a small, lipid membrane\uffe2\uff80\uff90perforating peptide. It is envisioned that the presented technology will impact the fields of biology, bioanalytics, and pharmacology from fundamental research and disease diagnostics to drug development.Metasurfaces have emerged as a breakthrough platform for manipulating light at the nanoscale and enabling on\uffe2\uff80\uff90demand optical functionalities for next\uffe2\uff80\uff90generation biosensing, imaging, and light\uffe2\uff80\uff90generating photonic devices. However, translating this technology to practical applications requires low\uffe2\uff80\uff90cost and high\uffe2\uff80\uff90throughput fabrication methods. Due to the limited choice of materials with suitable optical properties, it is particularly challenging to produce metasurfaces for the technologically relevant mid\uffe2\uff80\uff90infrared spectral range. These constraints are overcome by realizing functional metasurfaces on almost completely transparent free\uffe2\uff80\uff90standing metal\uffe2\uff80\uff90oxide membranes. A versatile nanofabrication process is developed and implemented for highly efficient dielectric and plasmonic mid\uffe2\uff80\uff90infrared metasurfaces with wafer\uffe2\uff80\uff90scale and complementary metal\uffe2\uff80\uff93oxide\uffe2\uff80\uff93semiconductor (CMOS)\uffe2\uff80\uff90compatible manufacturing techniques. The advantages of this method are revealed by demonstrating highly uniform and functional metasurfaces, including high\uffe2\uff80\uff90Q structures enabling fine spectral selectivity, large\uffe2\uff80\uff90area metalenses\uffc2\uffa0with\uffc2\uffa0diffraction\uffe2\uff80\uff90limited focusing capabilities, and birefringent metasurfaces providing polarization control at record\uffe2\uff80\uff90high conversion efficiencies.\uffc2\uffa0 Aluminum plasmonic devices and their integration into microfluidics for real\uffe2\uff80\uff90time and label\uffe2\uff80\uff90free mid\uffe2\uff80\uff90infrared biosensing of proteins and lipid vesicles are further demonstrated. The versatility of this approach and its compatibility with mass\uffe2\uff80\uff90production processes bring infrared metasurfaces markedly closer to commercial applications, such as thermal imaging, spectroscopy, and biosensing.Insights into the fascinating molecular world of biological processes are crucial for understanding diseases, developing diagnostics, and effective therapeutics. These processes are complex as they involve interactions between four major classes of biomolecules, i.e., proteins, nucleic acids, carbohydrates, and lipids, which makes it important to be able to discriminate between all these different biomolecular species. In this work, a deep learning\uffe2\uff80\uff90augmented, chemically\uffe2\uff80\uff90specific nanoplasmonic technique that enables such a feat in a label\uffe2\uff80\uff90free manner to not disrupt native processes is presented. The method uses a highly sensitive multiresonant plasmonic metasurface in a microfluidic device, which enhances infrared absorption across a broadband mid\uffe2\uff80\uff90IR spectrum and in water, despite its strongly overlapping absorption bands. The real\uffe2\uff80\uff90time format of the optofluidic method enables the collection of a vast amount of spectrotemporal data, which allows the construction of a deep neural network to discriminate accurately between all major classes of biomolecules. The capabilities of the new method are demonstrated by monitoring of a multistep bioassay containing sucrose\uffe2\uff80\uff90 and nucleotides\uffe2\uff80\uff90loaded liposomes interacting with a small, lipid membrane\uffe2\uff80\uff90perforating peptide. It is envisioned that the presented technology will impact the fields of biology, bioanalytics, and pharmacology from fundamental research and disease diagnostics to drug development.