Microfluidic random number generator driven by water-head pressure and human finger push

Abstract

Random number (RN) generators are indispensable in scientific simulations, cryptography, and games. Generation of high-quality RNs with unpredictable and indecipherable characteristics, however, has generally required complex and sophisticated systems. This paper describes a microfluidic RN generator that relies only on a constant water-head pressure and the push action of a human. The RN generator is comprised of three units: an astable oscillator, a bistable switch, and a push-button membrane. A constant pressure fluid flow is converted to pulsatile, high and low pressure flows by the astable unit. At the moment of a random push and release of the membrane unit, the bistable unit retains and displays either a high or low pressure state resulting in generation of a random bit. Repeated operation of the random bit generator produces series of RNs. Taking advantage of the human interactions involved, the microfluidic RN generators were developed into two games: (i) a single RN generator that functions as a coin flip game, and (ii) a quadruple RN generator that substitutes for four four-sided pyramid-shaped die and help play the Royal Game of Ur, commonly referred to as the world’s oldest board game. Importantly, a US National Institute of Standards and Technology (NIST) test of the RNs generated by the RN generator confirmed high quality randomness with unpredictability and unrepeatability ensuring that the games are fair.