A new technique, called nanoinjection, is being developed to insert foreign DNA into a living cell. Such DNA transfection is commonly used to create transgenic organisms vital to the study of genetics, immunology, and many other biological sciences. In nanoinjection, DNA, which has a net negative charge, is electrically attracted to a micromachined lance. The lance then pierces the cell membranes, and the voltage on the lance is reversed, repelling the DNA into the cell. It is shown that DNA motion is strongly correlated to ion transport through a process called electrophoresis. Gel electrophoresis is used to move DNA using an electric field through a gel matrix (electrolytic solution). Understanding and using electrophoretic principals, a mathematical model was created to predict the motion (trajectory) of DNA particles as they are attracted to and repulsed from the nanoinjector lance. This work describes the protocol and presents the results for DNA motion experiments using fabricated gel electrophoresis devices. Electrophoretic systems commonly use metal electrodes in their construction. This work explores and reports the differences in electrophoretic motion of DNA (decomposition voltage, electrical field, etc.) when one electrode is constructed from a semiconductor, silicon rather than metal. Experimental results are used to update and validate the mathematical model to reflect the differences in material selection. Accurately predicting DNA motion is crucial for nanoinjection. The mathematical model allows investigation of the attraction/repulsion process by varying specific parameters. Result show that the ground electrode placement, lance orientation and lance penetration significantly affect attraction or repulsion efficiency while the gap, lance direction, lance tip width, lance tip half angle and lance tip height do not. It is also shown that the electric field around the lance is sufficient to cause localized electroporation of cell membranes, which may significantly improve the efficiency of transport.



College and Department

Ira A. Fulton College of Engineering and Technology; Mechanical Engineering



Date Submitted


Document Type





BYU, MEMS, nanoinjector, DNA motion modeling, electrophoresis