Package Introduction

The SWOMPS program is a simulator built for solving active origami systems with complex multi-physics behaviors. The package can capture the large deformation folding, the heat transfer, the inter-panel contact, and the thermal-mechanically coupled actuation of active origami systems. The program provides five different loading methods and allows users to create loading schemes with arbitrary number and sequence of these methods. A list of related references are provided on the bottom of this page.

The code package can be found on GitHub at: 

Tutorial of using the package:

Simulation Models Available:

(1) Simulating electro-thermo-mechanically coupled actuation

In this work, we proposed a simulation method to capture the electro-thermo-mechanically coupled actuation of active origami systems rapidly and effectively. We modeled the heat transfer problem within the active origami using the planar triangular elements and simplifies the heat transfer between the origami and the surrounding environment as a 1D heat conduction problem. We compare the model against the micro-origami system we fabricated to calibrate and verify the validity of the model. 

(2) Simulating contact within origami structures

In this work, we proposed an efficient technique for simulating contact within origami structures. This work is published on Proceedings of Royal Society – A. We model the contact by introducing a barrier function (A contact potential) into the principle of stationary potential energy framework. This contact potential is designed such that a potential approaching infinity is obtained as the distance between the contacting panel and the contacting node approaches zero. We also find that the formulation also gives a practical method to model the thickness of origami. Simulation examples are provided to demonstrate the efficiency and the capability of the model.

(3) Simulating presence of compliant crease within origami

In this work, we proposed a method to simulate the presence of compliant creases within an origami structure. We introduces additional bar elements and rotational spring elements into the crease region to explicitly capture these creases with finite width. The bar areas are derived by matching the stiffness of the bar and hinge model to a theoretical plate model and the rotational spring stiffness is derived by matching the stiffness of the bar and hinge model to the pseudo-rigid-body model proposed by Howell. We verify the performance of this bar and hinge model by comparing it against the FE simulation for both small-strain loading and large-deformation loading and good agreements are obtained. We also showed that the model is significant for capturing the bistability and multistability within origami structures with compliant creases.


We would like to acknowledge the prior works from Ke Liu and Glaucio H. Paulino for establishing shared versions of nonrigid origami simulators. Their works paved the way for the new origami simulator, the origami contact, compliant crease, electro-thermal model presented in this package.


  1. Zhu, E. T. Filipov (2021). ‘Sequentially Working Origami Multi- Physics Simulator (SWOMPS): A Versatile Implementation’ (submitted)
  2. Zhu, E. T. Filipov (2021). ‘Rapid Multi-Physic Simulation for Electro-Thermal Origami Robotic Systems’ (submitted)
  3. Zhu, E. T. Filipov (2020). ‘A Bar and Hinge Model for Simulating Bistability in Origami Structures with Compliant Creases’ Journal of Mechanisms and Robotics, 021110-1.
  4. Zhu, E. T. Filipov (2019). ‘An Efficient Numerical Approach for Simulating Contact in Origami Assemblages.’ Proc. R. Soc. A, 475: 20190366.
  5. Zhu, E. T. Filipov (2019). ‘Simulating compliant crease origami with a bar and hinge model.’ IDETC/CIE 2019. 97119.
  6. Liu, G. H. Paulino (2018). ‘Highly efficient nonlinear structural analysis of origami assemblages using the MERLIN2 software.’ Origami^7.
  7. Liu, G. H. Paulino (2017). ‘Nonlinear mechanics of non-rigid origami – An efficient computational approach.’ Proc. R. Soc. A 473: 20170348.
  8. Liu, G. H. Paulino (2016). ‘MERLIN: A MATLAB implementation to capture highly nonlinear behavior of non-rigid origami.’ Proceedings of IASS Annual Symposium 2016.