ElViS Lesson
ElViS Lesson
Goal
Rheologic models consisting of combinations of linear elements, such as springs and dashpots, are widely used in biophysics to describe the mechanical and, in particular, the viscoelastic behavior of proteins, cells, tissue, and soft matter.
Even simple arrangements with few elements often suffice to recapitulate the experimental data and to provide biophysical insights, making them an ideal subject for educational purposes.
To provide students with an intuitive understanding of the mechanical behavior of spring and dashpot models, we describe a computer simulation tool, elastic viscous system simulator (ElViS), written in the JavaScript programming language for designing viscoelastic models via a graphical user interface and simulating the mechanical response to various inputs.
As an example application, we designed a virtual laboratory course using ElViS that teaches the basic principles of viscoelastic modeling in a gamelike manner.
Challenge
The project first originated as a playground tool, I build, to investigate spring-dashpot models. I quickly realized that this had a great educational potential. Unfortunately, shipping out this python based tool was not very smooth, so I created a javascript version instead that could be shared using a link.
The initial implementation used an iterative Runge-Kutta method to solve the differential equations for the arbitrary combinations of springs and dashpots. But as we use the models in the over-damped limit, e.g. a spring "jumping" to its destination, these infinities quickly lead to instabilities. Therefore, I derived a matrix-based analytic solution to solve the spring-dashpot system for any given point in time.
To actually use the tool in an educational setting, we quickly realized that just having a playground to create an intuition of spring-dashpot systems is not enough, we needed a more guided way. Therefore, I came up with the concept of short lessons where the student needs to derive an equation by experimenting with a given spring-dashpot setup.
The equation is evaluated against some "test-cases" to give the student feedback for their solution. This more challenging way to teach content proved to lead to longer lasting memorisation of the concepts.
Improved Learning
We then surveyed 50 undergraduate students of a 1-semester course in biophysics who participated in the virtual laboratory course. Students felt that the course was a helpful addition to the lecture and that it improved learning success.