Choose a device around you and analyzepredict its usefulness

Choose a device around you and analyze/predict its usefulness if it were to be scaled down to Nano scale. The device can be anything you find as useful, and which when scaled down in size would produce considerable benefits to you as well as the society as a whole. Remember to include quantifiable terminologies in your explanation. This answer depends primarily on your innovation, so, feel free to dream about future technologies while answering; because “Yesterday’s dream is today’s reality”.

Solution

A lock interface for cars and bank lockers.If a lock is made with nano size particles like nanoswitches,there is no need of key slot to insert a key.Instead with just a nano chip inserted into our finger nail can do the purpose with high security.This can help us in a lot of security issues we are finding these days.