MIT engineers have developed a paper-thin loudspeaker that turn any surface into an audio source. This thin-film loudspeaker produces sound with minimal distortion while using a fraction of the energy required by a traditional loudspeaker
Know more here – https://news.mit.edu/2022/low-power-thin-loudspeaker-0426

Here is another link with some more information on similar innovation – https://www.linkedin.com/posts/deepak-meka-9aab2a16_are-these-the-best-speakers-for-listening-activity-6927161992348659712-iWfa