Optical fiber sensor for non-contact monitoring of ICSI-pipettes

The injection of cells (e.g., sperm), subcellular organelles (e.g., nucleus), and solutes into cells (e.g., eggs) for cloning, embryology and molecular biology purposes are broadly practiced biological procedures. These cellular micro-injection operations are performed using drawn glass pipettes of microscopic diameters (as small as a few microns), which are extremely compliant structures. The pipette is pressed on the cell membrane causing a dimple until a predetermined tension is created. In the next phase, the membrane is pierced using various forcing techniques, and the pipette is driven into the cell. A non-contact sensor with high motion sensitivity is needed to monitor this delicate microscopic motion. We present an optical micro-device in this paper to achieve this objective. The main principle of the sensor is to detect the position and the orientation of a laser beam, which emanates from the pipette that is being monitored. We provide the technical specifications and the experimental verification of the concept.