Automated Embryo Manipulation and Rotation via Robotic nDEP-Tweezers

Abstract

Embryo manipulation is a fundamental task in assisted reproductive technology (ART). Nevertheless, conventional pick-place techniques often require proper alignment to avoid causing damage to the embryo and further, the tools have limited capability to orient the embryo being handled. In this paper, we present a novel and non-invasive technique that can easily manipulate embryos on a PVC Petri dish. An inverted microchip with quadrupole electrodes was attached to a micromanipulator to become a robotic dielectrophoresis (DEP) tweezers, and a motorized platform provides additional mobility to the embryos lying on a Petri dish. Vision-based algorithms were developed to evaluate relevant information of the embryos from the image, and to provide feedback signals for precise position and orientation control of the embryo. A series of experiments was conducted to examine the system performance, and the results confirm that the embryo can be successfully manipulated to a specified location with the desired orientation for subsequent processing. As the DEP tweezers can grasp the embryo without the need for precise alignment, the overall time required to process a large number of embryos can be shortened.

A Review of Single‐Cell Pose Adjustment and Puncture

“…Particles are polarized in an uneven electric field and interact with the applied electric field to generate a resultant force to move to the area of the strong electric field. The force model is defined as [79][80][81]…”

Electrically-driven handling of gametes and embryos: taking a step towards the future of ARTs

“…K. Huang et al proposed a nDEP microdevice with a proportional integral derivative (PID) controller for precise manipulation of mouse embryos. 128 The inverted microsystem consisting of quadrupole electrodes mounted on a motorized platform was utilized to transport, position and rotate murine embryos. Effects of chip height and input voltages were investigated and a set of parameters for safe handling was established.…”

Recent advances in critical nodes of embryo engineering technology

“…Dielectrophoresis (DEP) refers to the process in which oocytes are polarized in nonuniform electric fields and subjected to dielectrophoretic forces. Thus, oocytes can be controlled by adjusting electric field parameters to change the dielectrophoretic forces 62 - 64 . As shown in Figure 6 A , Huang et al 62 designed a dielectrophoretic chip consisting of four vertical carbon-black-nanoparticle-PDMS (C-PDMS) electrodes, an ITO electrode at the bottom, and a single cell trap/release module.…”

“…By applying multifrequency, multiamplitude, multiphase AC electrical signals to the microelectrodes, three-dimensional dielectric electrophoresis traps and one-dimensional electrical rotation can be generated simultaneously, realizing 4D single-cell manipulation. As shown in Figure 6 C , Huang et al 64 connected an inverted microchip with four electrodes to a manipulator as robotic dielectric electrophoresis tweezers to drive the embryo lying on the petri dish for rotation. A vision-based algorithm was developed to obtain the position and direction of the embryo and provide feedback signals to achieve precision control of the embryo.…”

“…(C) The effect of dielectrophoresis forceps and drive oocyte rotation. Adapted with permission from 62 , copyright 2018 Royal Society of Chemistry, and 63 , copyright 2018 John Wiley and Sons, and 64 , copyright 2020 IEEE.…”