A deeper understanding of human development and disease is made possible partly through the study of genetically modified model organisms, such as the common mouse (Mus musculus). By genetically modifying such model organisms, scientists can activate, deactivate, or highlight particular characteristics. A genetically modified animal is generated by adding exogenous (foreign) genetic material to one or more embryonic cells at their earliest stages of development. Frequently, this exogenous genetic material consists of specially engineered DNA, which is introduced into a fertilized egg cell (zygote). When successfully introduced into the zygote, the exogenous DNA will be incorporated into the cell's own genome, and the animal that develops from the zygote will exhibit the genetic modification in all of its cells. The current devices and methods for generating genetically modified animals are inefficient, and/or difficult to use. The most common and efficient method for inserting new DNA into zygotes is by directly injecting a DNA solution through a tiny glass tube into the cell in a process called microinjection. Unfortunately, microinjection is quite inefficient (success rates are commonly between 1 and 5%), but often it is the only method for inserting DNA into eggs, zygotes, or early stage embryos. This thesis presents the design and testing of a micrometer sale, pumpless microelectromechanical system (MEMS) nanoinjector. Rather than use pumps and capillaries, the nanoinjector employs electrostatic charges to attract and repel DNA onto and off of the surface of a solid lance. The nanoinjector also includes a mechanical system for constraining the target cells during injection. Initial testing indicates the nanoinjector does not decrease cell viability, and it has a very high initial success rate (up to 90%). With the addition of an on-chip actuator, the nanoinjector could be packaged as an inexpensive, fully automated system, enabling efficient, high volume genetic modification of developing animals. Such a device would greatly increase the ease and speed of generating the model organisms needed to study such critical diseases such as Alzheimer's disease, cancer, and diabetes.



College and Department

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



Date Submitted


Document Type





compliant, lamina emergent, metamorphic, MEMS, microinjection, microinjector, nanoinjector, transgenic, mouse, electrostatic, MUMPs