The newly-developed all-optical nanosensors are luminescent nanocrystals that can change intensity and/or color when you push or pull on them; they are probed with light only and therefore allow for fully remote read-outs — no wires or connections are needed; they have 100 times better force sensitivity than the existing nanoparticles that utilize rare-earth ions for their optical response, and an operational range that spans more than four...