When seawater penetrates concrete in road tunnels, a biofilm is formed that breaks down the concrete. This can lead to high costs and the risk of damage if stone and concrete drop from the tunnel roof.  In a new study, led by a team of researchers at Chalmers University of Technology in Sweden, research reveals the mechanisms behind the degradation, and its unexpectedly rapid progression.

Researchers have developed a machine learning workflow to optimize the output force of photo-actuated organic crystals. Using LASSO regression to identify key molecular substructures and Bayesian optimization for efficient sampling, they achieved a maximum blocking force of 37.0 mN—73 times more efficient than conventional methods. These findings could help develop remote-controlled actuators for medical devices and robotics, supporting applications such as minimally invasive surgery and precision drug delivery.

In a paper published in National Science Review, an international team of scientists reports dramatic, reversible p-n switching during the semiconductor-to-semiconductor phase transition of BiI₃ under pressure. They propose a novel method for determining carrier polarity based on the self-driven photocurrent dominated by the photothermoelectric effect. The study further reveals the correlation between the switching of positive and negative photoconductivity and the carrier type under high pressure.