Millions of international viewers enjoyed watching the reality TV show “Ice Road Truckers”, in which experienced truck drivers were expected to master scary challenges, such as transporting heavy supplies across frozen lakes in the remote Arctic. According to a new study published in the prestigious journal Earth’s Future by an international team of climate and lake scientists, crossing frozen lakes with heavy trucks may soon be a matter of the past.

The study is based on one of the most comprehensive future climate change model simulations to date (the Community Earth System Model ver. 2 Large Ensemble) to determine at which warming levels and unsafe ice conditions will be reached regionally with regard to transportation and recreational activities, including ice-fishing or ice-skating.

The conclusion of the study is straightforward, namely that global warming will make lake ice much less safe (Figure). This is likely to affect indigenous communities in the Arctic as well as regional economies, where people rely on ice roads as a means for fast and comparatively cheap transportation and supply during winter. Thinning future ice conditions also threaten unique lake ecosystems that have adapted to recurring frozen lake conditions over tens of thousands of years.

“Our results demonstrate that the duration of safe ice over the next 80 years will shorten by 2-3 weeks depending on the future warming level. In regions where lakes are used as ice roads to transport heavy goods and supplies, the number of days with safe ice conditions will decline by more than 90%, even for moderate warming of 1.5°C above early 20^th Century conditions”, says Dr. Lei Huang, corresponding author of the study and former postdoctoral researcher at the IBS Center for Climate Physics (ICCP), in Busan, South Korea.

“According to our computer model simulations, many densely populated regions in the mid-latitudes are projected to experience a large deterioration in safe ice conditions for recreational activities. Already a 1.5°C warming above early 20^th Century conditions can lead to more than 60% loss in the duration of safe lake ice. This will negatively impact local communities that rely on the ice recreation industry.” says Dr. Iestyn Woolway from Bangor University, in the UK, the first author of the study.

Dr. Sapna Sharma from York University in Canada, one of the lead authors, added, “Given that our planet has already warmed by 1.2°C since the beginning of industrialization, it is time to implement proper regional adaptation strategies in affected communities to mitigate economic losses and to avoid loss of lives.”

In a newly-published study, a team of researchers in Oxford University’s Department of Materials led by Harish Bhaskaran, Professor of Applied Nanomaterials, describe a breakthrough approach to pick up single nanowires from the growth substrate and place them on virtually any platform with sub-micron accuracy.

The innovative method uses novel tools, including ultra-thin filaments of polyethylene terephthalate (PET) with tapered nanoscale tips that are used to pick up individual nanowires. At this fine scale, adhesive van der Waals (tiny forces of attraction that occur between atoms and molecules) cause the nanowires to ‘jump’ into contact with the tips. The nanowires are then transferred to a transparent dome-shaped elastic stamp mounted on a glass slide. This stamp is then turned upside down and aligned with the device chip, with the nanowire then printed gently onto the surface.

Deposited nanowires showed strong adhesive qualities, remaining in place even when the device was immersed in liquid. The research team was also able to place nanowires on fragile substrates, such as ultra-thin 50-nanometre membranes, demonstrating the delicacy and versatility of the stamping technique.

In addition, the researchers used the method to build an optomechanical sensor (an instrument that uses laser light to measure vibrations) that was 20 times more sensitive than existing nanowire-based devices.

Nanowires, materials with diameters 1000 times smaller than human hair and fascinating physical properties, could enable major advancements in many different fields, from energy harvesters and sensors to information and quantum technologies. In particular, their minuscule size could allow the development of smaller transistors and miniaturized computer chips. A major obstacle, however, to realizing the full potential of nanowires has been the inability to precisely position them within devices.

Most electronic device manufacturing techniques cannot tolerate the conditions needed to produce nanowires. Consequently, nanowires are usually grown on a separate substrate and then mechanically or chemically transferred to the device. In all existing nanowire transfer techniques, however, the nanowires are placed randomly onto the chip surface, which limits their application in commercial devices.

DPhil student Utku Emre Ali (Department of Materials), who developed the technique, said: ‘This new pick-and-place assembly process has enabled us to create first-of-its-kind devices in the nanowire realm. We believe that it will inexpensively advance nanowire research by allowing users to incorporate nanowires with existing on-chip platforms, be it electronic or photonic, unlocking physical properties that have not been attainable so far. Furthermore, this technique could be fully automated, making full-scale fabrication of high-quality nanowire-integrated chips a real possibility.’

Professor Harish Bhaskaran (Department of Materials) added: ‘This technique is readily scalable to larger areas, and brings the promise of nanowires to devices made on any substrate and using any process. This is what makes this technique so powerful.’

The full paper, A Universal Pick-and-Place Assembly for Nanowires, is published in Small: https://onlinelibrary.wiley.com/doi/10.1002/smll.202201968

The work was funded by EPSRC via the Fellowships in Manufacturing (Grant no. EP/R001677/1).