Ultra-fast water-based switch could enable sci-fi technology

Holograms, 3D printers, and mobile phones were all first imagined in science fiction before being brought to life by scientists and engineers. Water-based technologies, not unlike those seen in the 1980s sci-fi classic, The Abyss, could be added to that list.

Buchmann et al. reported an ultra-fast switch created with a thin sheet of salty water and a laser. The switch functioned at terahertz frequencies – a thousand times faster than the semiconductor-based switches used in current computers, smartphones and wireless communications.

The switch combines previous findings in solid-state physics with basic principles of physical chemistry. To create the switch, a high concentration solution of sodium iodide in water was sprayed from a nozzle as a thin sheet. The liquid was then excited with a powerful blue laser. The researchers measured the conductivity with a terahertz field and found the salty water made a good electrical conductor at those frequencies.

“This is the largest signal of this kind ever detected in a liquid,” said author Fabio Novelli. “For a short time the water behaves almost like a metal and we see a signal comparable to ones from a solid-state material.”

Novelli hopes the findings will lead to new research avenues and water-based technologies, like those in The Abyss, which Novelli remembers from his childhood. Terahertz devices could someday enable much faster computing, and water-based technology could offer a more environmentally-friendly alternative to rare-earth metals.

“It’s a far reaching dream of mine that this work could be the inspiration that sparks new technologies,” Novelli said.

Source: “An ultra-fast liquid switch for terahertz radiation,” by Adrian Buchmann, Claudius Hoberg, and Fabio Novelli, APL Photonics (2022). The article can be accessed at https://doi.org/10.1063/5.0130236 .