# Simulation-Based Trajectory for Non-Planar Scaffold Printing on Irregular Patches Using Robotic Arm

## TL;DR

This paper introduces a new method for printing scaffolds on irregular surfaces using a robotic arm and simulation-based path optimization.

## Contribution

A simulation-based trajectory optimization system is integrated with a robotic arm for non-planar scaffold printing on anatomical surfaces.

## Key findings

- The method achieves positional accuracy within the robotic arm’s reproducibility threshold.
- The approach demonstrates superior geometric conformity on complex anatomical patches compared to traditional planar methods.
- The method enables controlled deposition of scaffolds on irregular surfaces using widely available tools like MATLAB.

## Abstract

This study proposes a reproducible and accessible methodological framework for non-planar path generation to enable scaffold biofabrication on irregular anatomical surfaces replicating the native morphology of human tissue. By integrating a simulation-based trajectory optimization system with a robotic arm, lattice paths are generated using an intersection-based method with parallel planes. This method is processed by intersecting the anatomical object with orthogonal planes, allowing for the creation of paths that conform to complex geometries. The proposed approach relies on widely available and commonly used tools, such as MATLAB, avoiding the need for highly specialized software. Thus, a MATLAB-based kinematic model computes optimal end-effector trajectories, while a coaxial nozzle facilitates the simultaneous extrusion of an alginate-based biomaterial. The proposed method ensures smooth trajectory execution, achieving positional standard deviation within the reproducibility threshold of the robotic arm for an optimal path discretization density. Unlike conventional planar methods, the optimized approach achieves positional accuracy within the robotic arm’s reproducibility threshold while demonstrating superior geometric conformity on complex anatomical patches. The approach successfully fabricates scaffolds with controlled deposition on anatomical patches, demonstrating improved geometric conformity over traditional planar methods. This method provides a pathway for patient-specific scaffold fabrication, supporting advances in tissue engineering and regenerative medicine.