A breakthrough in augmented-reality (AR) technology has been made by POSTECH researchers, which could revolutionize the way we interact with everyday life. The core AR device, typically bulky and heavy, can now be designed to be thin and light, making prolonged wear comfortable.

One of the main hurdles to commercializing AR glasses was the waveguide, a crucial component that guides virtual images directly to the user’s eye. Conventional designs required separate layers for red, green, and blue light, leading to increased weight and thickness. POSTECH researchers have eliminated this need by developing an achromatic metagrating that handles all colors in a single glass layer.

The key to this innovation lies in an array of nanoscale silicon-nitride pillars whose geometry was finely tuned using a stochastic topology-optimization algorithm to steer light with maximum efficiency. In experiments, the researchers produced vivid full-color images using a 500-µm-thick single-layer waveguide – about one-hundredth the diameter of a human hair.

The new design erases color blur while outperforming multilayer optics in brightness and color uniformity. This breakthrough has significant implications for the commercialization of AR glasses, which could become as thin and light as ordinary eyewear. The era of truly everyday AR is now within reach.

“This work marks a key milestone for next-generation AR displays,” said Prof. Junsuk Rho. “Coupled with scalable, large-area fabrication, it brings commercialization within reach.”

The study was carried out by POSTECH’s Departments of Mechanical, Chemical and Electrical Engineering and the Graduate School of Interdisciplinary Bioscience & Bioengineering, in collaboration with the Visual Team at Samsung Research. It was published online on April 30, 2025, in Nature Nanotechnology.

This research was supported by POSCO Holdings N.EX.T Impact, Samsung Research, the Ministry of Trade, Industry and Energy’s Alchemist Project, the Ministry of Science and ICT’s Global Convergence Research Support Program, and the Mid-Career Researcher Program.

The study, conducted by University of Bristol academics, has shed light on the importance of tailoring social media to suit individual needs. By categorizing users into distinct groups based on their motivations and behaviors, researchers have found that finding the right level of personal investment is key to a positive experience online.

The research revealed three main user types:

1. Those who browse without strong intentionality, often mindlessly scrolling through feeds.
2. Those deeply invested in their online lives, potentially leading to compulsive use and negative consequences for well-being.
3. Those who see value in using social media but retain personal distance, arguably having the best outcomes overall.

The findings suggest that social media platforms could be redesigned to support more intentional use by introducing customized features tailored to different user needs. This approach has the potential to help users regain control over their time online and make it more purposeful and valued.

By adapting interfaces to align with individual well-being, social media platforms can promote sustainable engagement connected to things that matter to the user, rather than just maximizing screen time. The implications of this work extend beyond social media design into technology use more broadly, offering a data-driven approach to promoting digital self-regulation and overall well-being.

The next phase of this research will explore how social media platforms can identify different user groups and adapt interfaces to support intentional online engagement that prioritizes personal well-being.

Smart home technologies are increasingly used worldwide to monitor and control various aspects of daily life. However, a growing concern has emerged regarding the impact of these devices on domestic workers, who often find themselves under constant surveillance.

Researchers from King’s College London have conducted a study that reveals the unsettling truth about smart home devices being used to monitor domestic workers in China. The study, which involved interviews with 26 domestic workers and five recruitment agencies, highlights how employers are using these technologies to exert control over their employees, undermining their privacy and safety.

The researchers found that many domestic workers felt like they were under constant observation, with cameras and sensors installed in every room of the smart home. Some reported not being informed about the presence of cameras, while others discovered them hidden in bookshelves or disguised as other devices.

The constant feeling of being watched had a profound impact on the mental wellbeing of these domestic workers. Many felt uneasy, anxious, and even trapped in their own homes. The researchers concluded that this level of surveillance amounts to mental abuse, undermining trust and affecting workplace interactions.

Furthermore, the study revealed how smart home technologies exacerbate existing power imbalances between workers and employers. Employers can use these devices to monitor workers’ performance, track their movements, and even make decisions about their employment based on data collected from the devices.

The researchers highlighted that while many domestic workers recognized the need for safety, especially when caring for babies, the absence of clear communication from employers about the purpose of monitoring sparked distrust and discomfort. They recommended that domestic worker agencies integrate privacy education into training programmes for workers to understand their rights and establish transparent communication and contractual agreements regarding surveillance practices.

The study was conducted by researchers from King’s College London, along with collaborators from the University of St Andrews and the China Academy of Art, Hangzhou. The findings suggest that this issue is not unique to China but may be affecting migrant domestic workers worldwide.

In conclusion, the use of smart home technologies to monitor domestic workers raises significant concerns about their safety and privacy. The researchers’ recommendations provide a starting point for policymakers and agencies to address these challenges and ensure that domestic workers are protected from exploitation. As technology continues to advance, it is crucial that we prioritize human rights and dignity in the development and implementation of smart home devices.