As the post-lunch slump sets in, many office workers opt for a coffee or chocolate to keep their eyes open, risking sleeplessness or a sugar crash. It is at times like this, its inventors believe, that a new wearable device can stimulate users via a tiny pulse that will heighten their mood or bring it down if they want to relax.
Image: The creators claim Doppel helps make users more alert or relaxed. Founders from left are: Nell Bennett, Jack Hooper, Andreas Bilicki and Fotini Markopoulou. Photograph: Martin Godwin for the Guardian
