Fabrication of a silicon μDicer for uniform microdissection of tissue samples

Generating uniform tissue microfragments is important in many applications, including disease diagnostics, drug screening, spatial-omics, and fundamental wound healing and tissue regeneration studies. Common mechanical dissection methods, such as manual mincing, are imprecise and result in fragments with a broad range in size. This work aims to develop a microscale dicing device, referred to as the mu Dicer, consisting of a hollow array of blades spaced hundreds of micrometers apart. A tissue pushed through this array is diced into many microfragments simultaneously. The focus of this paper is on the fabrication process of the mu Dicer using a combination of isotropic and anisotropic etching in silicon. A single silicon oxide etch mask is used in a dry silicon etcher for both a tapered etch to form the microblades, and an anisotropic etch to form the through-holes in the hollow blade array. The use of a single mask reduces the mask fabrication time by more than twofold compared with two-mask approaches often used to generate similar etch features. The etch parameters and the design of the etch mask control the blade angles and the edge profiles of the blades. Specifically, the incorporation of notches in the two-dimensional mask design generates three-dimensional microserrated features on the blade edges. A custom, open-source etching model is also developed to facilitate the prediction of the etch profiles. Finally, a proof-of-concept application of the mu Dicer to dissect soft materials and tissues is demonstrated.

Automated summary

The study focuses on developing a microscale dicing device called mu Dicer, utilizing a combination of isotropic and anisotropic etching in silicon. The fabrication process is optimized to reduce time and successfully demonstrates the application of dissecting soft materials and tissues.