Characterization of 3D printed micro-blades for cutting tissue-embedding material

TL;DR

This study uses precise 3D printing to fabricate micro-blades with controlled geometries, systematically analyzing how blade tip radius and configuration affect cutting energy in tissue-embedding materials, advancing microscale tissue cutting techniques.

Contribution

It introduces a method to fabricate and study micro-blades with controlled geometries, revealing how tip radius and blade arrangement influence cutting performance on soft materials.

Findings

Cutting energy decreases with smaller blade tip radius until ~357 nm.

Blade configuration affects cutting energy, scaling linearly with total blade length.

Precise fabrication enables systematic study of microscale cutting mechanics.

Abstract

Cutting soft materials on the microscale has emerging applications in single-cell studies, tissue microdissection for organoid culture, drug screens, and other analyses. However, the cutting process is complex and remains incompletely understood. Furthermore, precise control over blade geometries, such as the blade tip radius, has been difficult to achieve. In this work, we use the Nanoscribe 3D printer to precisely fabricate micro-blades (i.e., blades <1 mm in length) and blade grid geometries. This fabrication method enables a systematic study of the effect of blade geometry on the indentation cutting of paraffin wax, a common tissue-embedding material. First, we print straight micro-blades with tip radius ranging from ~100 nm to 10 um. The micro-blades are mounted in a custom nanoindentation setup to measure the cutting energy during indentation cutting of paraffin. Cutting energy, measured as the difference in dissipated energy between the first and second loading cycles, decreases as blade tip radius decreases, until ~357 nm when the cutting energy plateaus despite further decrease in tip radius. Second, we expand our method to blades printed in unconventional configurations, including parallel blade structures and blades arranged in a square grid. Under the conditions tested, the cutting energy scales approximately linearly with the total length of the blades comprising the blade structure. The experimental platform described can be extended to investigate other blade geometries and guide the design of microscale cutting of soft materials.