Filling-and-Dragging Technique for A Particle-Entrapment Using Triangular Microwells

Abstract

Trapping particle such as a cell, cell spheroid or scaffold bead, in a large trapping spot, such as a microwell, is important in various biological aspects. To achieve high trapping efficacy, the management of two countering effects from hydrodynamic and gravitational force is a key requirement. To increase the possibility of controllable entrapment, this study proposed a new approach using the filling and dragging technique to trap particles. The investigation of the trapping efficacy in three different triangular microwells such as obtuse, equilateral and acute triangle was conducted. The extremely low flow rate was firstly introduced to fill the particles in the microwell, and the flow rate was subsequently increased to drag and rearrange the entrapped particles. High trapping rate of a single particle in an equilateral triangular microwell could reach 80% when trapping polystyrene beads. For biomaterial particle such as cell spheroid, the adhesiveness with the other and the microwell surface is the parameter that needs to be further investigated.