Levitating sensor for magnetic fields could detect ultrafaint brain activity

TL;DR - A Nature news item on a levitated-mass magnetic field sensor whose mechanically simple design reportedly matches far more complex magnetometers, with proposed uses in detecting ultrafaint brain activity and in dark-matter searches. Content available is only the title and abstract blurb, so specifics (sensitivity, materials, setup) are inferred as unstated.

• Core claim: a levitating sensing element is used to transduce very weak magnetic fields, targeting biomagnetic signals from neural activity (the regime normally requiring SQUIDs or optically pumped magnetometers).
• Stated advantage is design simplicity rather than a new sensitivity record — the blurb says it "could rival" much more complex alternatives, without quantified figures in the provided text.
• Two application domains are named: biophysics/neuroscience measurement and fundamental-physics searches for dark matter, implying broadband ultra-low-field sensitivity.
• No AI/ML component is described; relevance to an AI digest is upstream — richer, cheaper magnetoencephalography-class data would expand training and decoding datasets for neural signal models.