Design and fabrication of a micro-compliant organoid trap

Abstract

Cerebral brain organoids are valuable three-dimensional models for studying early human brain development and disease. However, their soft, delicate structure makes mechanical characterization challenging, as existing trapping mechanisms often rely on actuation or fixation methods that can damage or compromise sample integrity. To address this limitation, this study presents the development of a novel micro-scale organoid trap based on a compliant bistable mechanism. The trap is designed to hold a cerebral organoid proxy through weight-triggered bistability. The mechanism was fabricated using light-assisted 3D microfabrication via two-photon polymerization, and different printing strategies were explored to achieve a low activation force for the bistable response. The selected material has a low Young’s modulus to approximate the natural mechanical environment of brain tissue. Experimental characterization was performed using a nanoindentation setup to obtain the material properties and the bistable force–displacement curve. Ultimately, this work aims to establish a microfabricated bistable compliant mechanism that enables non-invasive and untethered grasping of cerebral organoid proxies to support mechanical characterization and facilitate distinction between healthy and diseased tissue models.