Liquid marble interaction gate for collision-based computing

Thomas C Draper,Neil Phillips,Claire Fullarton,Andrew Adamatzky,Ben P.J De Lacy Costello

doi:10.1016/j.mattod.2017.09.004

Abstract

Liquid marbles are microliter droplets of liquid, encapsulated by self-organized hydrophobic particles at the liquid/air interface. They offer an efficient approach for manipulating liquid droplets and compartmentalizing reactions in droplets. Digital fluidic devices employing liquid marbles might benefit from having embedded computing circuits without electronics and moving mechanical parts (apart from the marbles). We present an experimental implementation of a collision gate with liquid marbles. Mechanics of the gate follows principles of Margolus’ soft-sphere collision gate. Boolean values of the inputs are given by the absence (FALSE) or presence (TRUE) of a liquid marble. There are three outputs: two outputs are trajectories of undisturbed marbles (they only report TRUE when just one marble is present at one of the inputs), one output is represented by trajectories of colliding marbles (when two marbles collide they lose their horizontal momentum and fall), this output reports TRUE only when two marbles are present at inputs. Thus the gate implements AND and AND-NOT logical functions. We speculate that by merging trajectories representing AND-NOT output into a single channel one can produce a one-bit half-adder. Potential design of a one-bit full-adder is discussed, and the synthesis of both a pure nickel metal and a hybrid nickel/polymer liquid marble is reported.

Highlights

Since their inception in 2001 [1], liquid marbles (LMs) have been a source of growing interest across fields as diverse as medicine [2, 3], engineering [4, 5]Preprint submitted to Materials Today and chemistry [6, 7]
This demonstration of a collision interaction gate represents the first computing device operated by LMs
A new automatic technique for the easy and reproducible synthesis of LMs enhances the reliability of gate operations

Summary

Introduction

Since their inception in 2001 [1], liquid marbles (LMs) have been a source of growing interest across fields as diverse as medicine [2, 3], engineering [4, 5]Preprint submitted to Materials Today and chemistry [6, 7]. LMs are constructed from microlitre droplets of water, 5 supported by a layer of hydrophobic particles on the surface. In this manner, the hydrophobic particles minimise the comparatively high surface energy of water by encapsulating the droplet, and keeping it near spherical. The hydrophobic particles minimise the comparatively high surface energy of water by encapsulating the droplet, and keeping it near spherical This permits the water droplet to remain non-wetting on many (traditionally wettable) surfaces. The coating provides the largest affect on the mechanical properties of the marble, as it is the coating that interacts with the surface the LM is resting on. It is possible to adapt a liquid marble to many different situations

Methods

Discussion

Conclusion