Biomaterials

Project — Finite Element Analysis of Natural Biomaterials Using 3D Scanning

1 Introduction

In this project, you will explore how computational methods can be applied to study the mechanical behavior of biomaterials. We will focus on the Finite Element Method (FEM) — a powerful computational approach that allows us to simulate how structures respond to external forces such as tension, compression, or bending.

By combining photogrammetry, 3D modeling, and finite element simulation, you will gain hands-on experience in translating real-world biological structures (e.g. bones, shells, insect exoskeletons, or plant stems) into computational models that can be tested virtually.

This activity connects our earlier discussions on stress–strain relationships, elasticity, and toughness with modern computational tools used in biomaterial research.

2 Learning Objectives

By the end of this project, you will be able to:

• Capture 3D geometry of natural biomaterials using smartphone photogrammetry.
  
• Clean and prepare meshes in Blender and export to .stl.
  
• Set up and run a linear elasticity simulation in PrePoMax.
  
• Interpret displacement and stress fields (e.g., von Mises) in the context of structure–function relationships.

3 Group Setup & Materials

• Work in groups of six (6).
  
• Each group will select one biomaterial specimen that can be found around campus — such as a small bone, seashell, bamboo, seed pod, or insect exoskeleton.
• Required apps/software (install before class):
  • Kiri Engine (smartphone app) — for photogrammetry
    
  • Blender — for mesh cleanup and export
    
  • PrePoMax — for FEA (linear elasticity)

4 Step-by-Step Instructions

4.1 Photogrammetry (3D Scanning using Smartphone)

• Install Kiri Engine (Kiriengine) app on your phone.
• Watch the tutorial: How to scan objects with Kiri Engine
• Capture your biomaterial object following these tips:
  • Use good lighting and a neutral background.
  • Take photos around the object from multiple angles (at least 40–60 shots), or use video.
  • Upload and generate the 3D model using the app’s cloud processing.
  • Export your model as .obj and share it within your group.

4.2 Cleaning and Preparing the 3D Model

• Open the exported model in Blender.
• Clean the mesh:
  • Remove background or unwanted geometry.
  • Fill any holes or gaps using mesh editing tools.
  • Scale and orient the object correctly (Z-axis upright).
  • Export the final cleaned model as an .stl file.

4.3 Finite Element Simulation with PrePoMax

• Follow the tutorial: PrePoMax FEM Tutorial
• Import your .stl model into PrePoMax.
• Define the material properties (choose an appropriate biomaterial, e.g., bone, chitin, or plant fiber).
• Apply boundary conditions:
  • Fix one side of the object.
  • Apply a small tensile or compressive load on the other side.
  • Run the linear elasticity simulation.
• Visualize and record:
  • Stress distribution (von Mises)
  • Deformation map
  • Displacement results

5 Safety, Ethics, and Permissions

• Only collect non-hazardous specimens; do not harm living organisms.
  
• If uncertain about ethics/permits, consult the teaching staff.
  
• Clean and return any borrowed items; follow lab safety guidance.