Helium is tiny, and will diffuse though pretty much anything other than continuous welded metal pipe very very quickly. The elastomer seals on a phone would slow it down slightly, but the article’s from 2018, before so many phones were watertight. I remember my old iPhone had a little piezo cooling fan in one of the grates on the bottom, so helium would have no trouble at all.
Helium is tiny, and will diffuse though pretty much anything other than continuous welded metal pipe very very quickly. The elastomer seals on a phone would slow it down slightly, but the article’s from 2018, before so many phones were watertight. I remember my old iPhone had a little piezo cooling fan in one of the grates on the bottom, so helium would have no trouble at all.