University of California

Indiana University

Masa P Rao

Noel C MacDonald

Brian Thibeault

Frederick F Lange

Marco F Aimi

Yanyan Zhang

Emily R Parker

Chris Ballas

Antonio Javier Sanchez Herencia

Many applications in cell biology, genetic engineering, cell-based therapeutics, and drug discovery require precise and safe methods for introducing membrane-impermeable molecules into cells. This can be implemented satisfactorily by microinjection. However, disadvantages of traditional manual microinjection include high degree of operator skill, low throughput and labor-intensiveness. Many studies have focused on developing automated and high-throughput systems for microinjection to address these limitations. However, none have provided sufficient throughput for applications such as ex vivo cell therapy, where manipulation of many cells is helpful.

Ultrahigh throughput microinjection device

Monocyclic chlorine based inductively coupled plasma deep etching processes for the rapid micromachining of titanium substrates and titanium devices so produced are disclosed. The method parameters are adjustable to simultaneously vary etch rate, mask selectivity, and surface roughness and can be applied to titanium substrates having a wide variety of thicknesses to produce high aspect ratio features, smooth sidewalls, and smooth surfaces. The titanium microdevices so produced exhibit beneficially high fracture toughness, biocompatibility and are robust and able to withstand harsh environments making them useful in a wide variety of applications including microelectronics, micromechanical devices, MEMS, and biological devices that may be used in vivo.

Monocyclic high aspect ratio titanium inductively coupled plasma deep etching processes and products so produced

Reliable, flaw-tolerant brittle materials are produced by incorporating layers under residual compression on the surface and throughout the bulk of the material that act to trap and contain the propagation of otherwise catastrophic cracking. The residual compression within these layers acts to reduce the stress intensity of the cracks, thereby causing them to arrest until further loading is provided. This highly desirable stable, subcritical crack growth mode persists with increased loading until the applied stress is large enough to drive the crack completely through compressive region, after which failure occurs. The exact level of stress needed to accomplish this is dictated by the architectural design of the compressive layers such that the material can be designed to have any minimum strength desired, within the limits of the materials system used. This results in a truncation of the strength distribution, such that there is virtually zero probability of failure below this minimum value, i.e. the material possesses a threshold strength. Consequently, sensitivity to flaws that would ordinarily cause catastrophic failure at stresses below the threshold strength is eliminated. Furthermore, the potential exists for the complete elimination of the strength variability, hence improving reliability, through the creation of nearly deterministic, i.e. single-valued, strengths by increasing the threshold strength above the stresses at which failure normally initiates from intrinsic flaws.

Method for improving the reliability of brittle materials through the creation of a threshold strength

Growing community of inventors

Santa Barbara, CA, United States of America

Masa P Rao