Researchers at Swinburne University of Technology, collaborating with Monash University, have developed an ultrathin, flat, ultra-lightweight graphene oxide optical lens with unprecedented flexibility. The ultrathin lens enables potential applications in on-chip nanophotonics and improves the conversion process of solar cells. It also opens up new avenues in:
Optical lenses are indispensable components in almost all aspects of technology including imaging, sensing, communications, and medical diagnosis and treatment. The rapid development in nano-optics and on-chip photonic systems has increased the demand for ultrathin flat lenses with three-dimensional subwavelength focusing capability – the ability to see details of an object smaller than 200 nanometres. Recent breakthroughs in nanophotonics have led to the development of a number of ultrathin flat lens concepts, however their real-life application is limited due to their complex design, narrow operational bandwidth and time consuming manufacturing processes. “Our lens concept has a 3D subwavelength capability that is 30 times more efficient, able to tightly focus broadband light from the visible to the near infrared, and offers a simple and low-cost manufacturing method,” research leader in nanophotonics at Swinburne’s Centre for Micro-Photonics (CMP), Associate Professor Baohua Jia, said. The researchers produced a film that is 300 times thinner than a sheet of paper by converting graphene oxide film to reduced graphene oxide through a photoreduction process. “These flexible graphene oxide lenses are mechanically robust and maintain excellent focusing properties under high stress,” lead author of the research, PhD candidate Xiaorui Zheng said. “They have the potential to revolutionise the next-generation integrated optical systems by making miniaturised and fully flexible photonics devices.” CMP Director, Professor Min Gu, said: “The newly demonstrated laser nano-patterning method in graphene oxides holds the key to fast processing and programming of high capacity information for big data sectors.” Professor Dan Li, Co-director of the Monash Centre for Atomically Thin Material, which provided the graphene oxide film for this research said this work opens up a new high-tech application for graphene oxide and demonstrates how nanotechnology can add significant value to natural graphite. The research is published in ("Highly efficient and ultra-broadband graphene oxide ultrathin lenses with three-dimensional subwavelength focusing") and has been funded by the Australian Research Council under its Discovery Early Career Researcher Award, Discovery Project and Laureate Fellowship scheme.
read more "Ultrathin graphene oxide lens could revolutionise next-gen devices"
- – non-invasive 3D biomedical imaging
- – photonic chips
- – aerospace photonics
- – micromachines
- – laser tweezing – the process of using lasers to trap tiny particles.
Optical lenses are indispensable components in almost all aspects of technology including imaging, sensing, communications, and medical diagnosis and treatment. The rapid development in nano-optics and on-chip photonic systems has increased the demand for ultrathin flat lenses with three-dimensional subwavelength focusing capability – the ability to see details of an object smaller than 200 nanometres. Recent breakthroughs in nanophotonics have led to the development of a number of ultrathin flat lens concepts, however their real-life application is limited due to their complex design, narrow operational bandwidth and time consuming manufacturing processes. “Our lens concept has a 3D subwavelength capability that is 30 times more efficient, able to tightly focus broadband light from the visible to the near infrared, and offers a simple and low-cost manufacturing method,” research leader in nanophotonics at Swinburne’s Centre for Micro-Photonics (CMP), Associate Professor Baohua Jia, said. The researchers produced a film that is 300 times thinner than a sheet of paper by converting graphene oxide film to reduced graphene oxide through a photoreduction process. “These flexible graphene oxide lenses are mechanically robust and maintain excellent focusing properties under high stress,” lead author of the research, PhD candidate Xiaorui Zheng said. “They have the potential to revolutionise the next-generation integrated optical systems by making miniaturised and fully flexible photonics devices.” CMP Director, Professor Min Gu, said: “The newly demonstrated laser nano-patterning method in graphene oxides holds the key to fast processing and programming of high capacity information for big data sectors.” Professor Dan Li, Co-director of the Monash Centre for Atomically Thin Material, which provided the graphene oxide film for this research said this work opens up a new high-tech application for graphene oxide and demonstrates how nanotechnology can add significant value to natural graphite. The research is published in ("Highly efficient and ultra-broadband graphene oxide ultrathin lenses with three-dimensional subwavelength focusing") and has been funded by the Australian Research Council under its Discovery Early Career Researcher Award, Discovery Project and Laureate Fellowship scheme.
The sensing principle is straightforward: the diagnostically relevant protein (green or red), if present, binds to an electro-active DNA strand and limits the ability of this DNA to hybridize to its complementary strand located on the surface of a gold electrode. This causes a reduction of electrochemical signal, which can be easily measured using inexpensive devices similar to those used in the home glucose self-test meter. Using this sensor, the researchers were able to detect several proteins directly in whole blood in less than 10 minutes. (Image: Ryan & Peter Allen) The new technology may also drastically impact global health, due to its low cost and easiness of use, according to the research team. The rapid and easy-to-use diagnostic tests are made of DNA and use one of the simplest force in chemistry, steric effects - a repulsion force that arises when atoms are brought too close together - to detect a wide array of protein markers that are linked to various diseases. The design was created by the research group of Alexis Vallée-Bélisle, a professor in the Department of Chemistry at University of Montreal. "Despite the power of current diagnostic tests, a significant limitation is that they still require complex laboratory procedures. Patients typically must wait for days or even weeks to receive the results of their blood tests," Vallée-Bélisle said. "The blood sample has to be transported to a centralised lab, its content analyzed by trained personnel, and the results sent back to the doctor's office. If we can move testing to the point of care, or even at home, it would eliminates the lag time between testing and treatment, which would enhance the effectiveness of medical interventions." The key breakthrough underlying this new technology came by chance. "While working on the first generation of these DNA-base tests, we realised that proteins, despite their small size (typically 1000 times smaller than a human hair) are big enough to run into each other and create steric effect (or traffic) at the surface of a sensor, which drastically reduced the signal of our tests," said Sahar Mashid, postdoctoral scholar at the University of Montreal and first author of the study. "Instead of having to fight this basic repulsion effect, we instead decided to embrace this force and build a novel signaling mechanism, which detects steric effects when a protein marker binds to the DNA test." The sensing principle is straightforward: the diagnostically relevant protein (green or red), if present, binds to an electro-active DNA strand, and limits the ability of this DNA to hybridize to its complementary strand located on the surface of a gold electrode. Francesco Ricci, a professor at University of Rome Tor Vergata who also participated in this study, explains that this novel signaling mechanism produces sufficient change in current to be measured using inexpensive electronics similar to those in the home glucose test meter used by diabetics to check their blood sugar. Using this DNA-base assay, the researchers were able to detect multiple protein markers directly in whole blood in fewer than 10 minutes, even if their concentration is 1,000 000 times less concentrated than glucose. "A great advantage of this DNA-based electrochemical test is that its sensing principle can be generalized to many different targets, allowing us to build inexpensive devices that could detect dozens of disease markers in less than five minutes in the doctor's office or even at home," concludes Vallée-Bélisle. A patent has been submitted for this invention, and many other applications are envisaged, including pathogen detection in food or water and therapeutic drug monitoring at home, a feature which could drastically improve the efficient of various class of drugs and treatments.