How researchers unlocked the future of self-cleaning surfaces.
Researchers from the University of Edinburgh and the University of Warwick recently published a study detailing the methods that some insects use to remove surface contaminants. This study used a molecular simulation tool called Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) to understand the interactions between the contaminant and surface particles at the nano level.

Sreehari Perumanath, Rohit Pillai and Matthew Borg published their findings, “Contaminant Removal from Nature’s Self-Cleaning Surfaces,” in the May 2023 issue of Nano Letters. The article discusses how engineers have taken inspiration from the self-cleaning properties of winged insects, like the cicada, and determined the underlying science behind the phenomena. This opens the door to improvements in various industries, ranging from electronics manufacturing, biosensor research and space exploration—as all experience issues when surfaces contain contaminates.
Engineers tend to think of engineering simulation in terms of structure, thermal and computational fluid dynamics (CFD), but more applications are coming online every day. Simulating materials at the molecular level can result in new applications of technology and the possibility of new products and processes. Today, researchers and engineers have a unique opportunity to study and communicate the underlying principles behind these phenomenon using analysis and simulation. Doing so could result in more sustainable products, processes and systems overall. So, let’s learn about LAMMPS and how it can help in this endeavor.
What Is LAMMPS?
The Large-scale LAMMPS had its first public release back in 2004 as a C++ tool. But compared to other simulation tools, LAMMPS was focused on very specific and very small simulations.
There’s a laundry list of functions that the software can perform, with the main functions being atomic models, interactions between particles and assessing the constraints and boundaries associated with these particles. But this is an open-sourced tool. So, unlike a lot of the tools engineers are used to, LAMMPS doesn’t offer a full-service parametric CAD to results and reports workflow. Instead, it is one important part in a chain of tools. The LAMMPS website puts it this way: the software “is designed to be a fast, parallel engine for molecular dynamics (MD) simulations. It provides only a modest amount of functionality for setting up simulations and analyzing their output.”
The website even includes a frank discussion of what LAMMPS does not do on its non-features page. But in doing so, it offers help. For instance, even though the software does not provide GUI input, automatic force assignments and field coefficients or output data plots, the page shows at least one alternative for each one of these functions. This enables researchers and engineers who are looking for a full workflow experience to get one. Many of these partner tools are built from Python and the most prominent is Pizza.py, which functions as a visualization tool for results. Since LAMMPS is open-source, its documentation, training tools and example calculations are available.
Self-Cleaning Lessons from Insect Wings
Perumanath, Pillai and Borg used LAMMPS to create molecular dynamic simulations to understand why some particles are pulled away from hydrophobic surfaces while some particles stay. The team broke the system into two categories of interaction. According to the Nano Letters article, “a higher attractive force from the condensate liquid relative to the adhesive force results in floating removal.” This contrasts with lifting removal, which is caused by surface tension forces that come into play when water droplets move into a more hot-air balloon shape and the stiffness of the surface can act as a linear spring.
The first application of these findings that come to mind is solar panels. Cleaning solar modules and arrays is recommended by manufacturers to maintain high energy efficiency and increase the life of the devices. Applying a coating formulated from the study’s results could keep modules clean longer and lead to massive benefits over time. Automotive cameras, like backup cameras, could also benefit from these findings as cleaner surfaces can see and transmit more data to the driver.
But window washers and windshield wiper manufacturers don’t have to worry about finding new jobs yet because there is more work to be done. However, the possibility of self-cleaning surfaces is promising.
The Bridge Between Engineering Simulation and Molecular Simulation
The term engineering simulation brings to mind a fairly specific subset of tools for most people. We think about finite element analysis and performing structural analysis, computational fluid dynamics, thermal analysis and other fundamental engineering studies. Electronics design automation has found vast amounts of growth in the last decade as the world hurries to electrify vehicles and add connectivity to everyday objects. But there still are many tools out there simulating other aspects of scientific discovery that are yet to be used by the engineering community.
One example of this includes a concept led Dassault Systèmes to create BIOVIA. Housed within the same 3DEXPERIENCE framework that many of us are already familiar with, BIOVIA helps scientists and researchers to move from ideas to fully formed manufacturing plans. Some of the tools feel as though we’re mapping the scientific method into a product lifecycle management (PLM) format, but there are others that are wholly in the simulation realm. The suite of tools includes a Discovery Studio that is similar to the molecular simulations used in the surface contaminant study. But the LAMMPS website and tools can be described as no frills and open sourced, whereas BIOVIA looks polished and inviting like the rest of the 3DEXPERIENCE software—which is reflected in its premium price tag.
Even though we are talking about molecular simulation, instead of structural, the goals are almost the same. Users want results on a virtual level to understand how the products and processes should work before moving into a physical testing phase. The simulations are taking inputs from the user and comparing the variables to decades’ worth of data to understand how the particles will react. Finally, the results of the studies, when completed, are available to people across the organization in customizable formats.
The discovery of new materials and their application has the opportunity to have a huge impact on society in the next few decades. Climate change is bringing new challenges related to how humans coexist with nature, so engineers and researchers have enormous opportunities to make a big impact. Simulations built with a high degree of fidelity will give us even more insights into how the technological and natural worlds can interact.