LAUSR

bedded sensors and provide a more economical and practical energy solution. On the other hand, if we have a multitude of devices in our environments that must last decades, energy harvesting may be mandated, and here we will need area for photovoltaics, thermoelectrics, piezoelectrics, or even, as in this case, perhaps triboelectrics or maybe RF or inductive energy receivers. Large flat sheets provide such area, and researchers have built systems using all of these approaches (see ‘The Superpowers of Super-Thin Materials,’ NYT Jan. 7, 2020), even building sensors and electronics into fibers and fabrics, but it’s not yet clear what the driving applications are. We will see flexible display ‘wallpaper’ in the not too distant future, but this will definitely be a powered system (this world will witness an interesting tension between photons beamed to our retinas via ubiquitous AR glasses vs light from everywhere displays). Perhaps its first market will be in building materials (for example, passively detecting dampness, strain, or temperature, after they are installed, as envisioned in my team’s original ‘Sensor Tape’ project from 2012). Passive sensate structures, as espoused in this paper, will enable sensing everywhere. We are already living in a world where networked sensing risks privacy behind every door—once our commonplace materials beam new streams of ubiquitous sensor data, this reaches another level, as even coarse but plentiful data can leverage potentially invasive contextual determination. The paper describes some simple ideas of physically ‘opting in’ with these materials, but I think the details of how privacy will be managed will be much more complex when life is enveloped with so many digital peepholes looking at us from everything.