Manipulation Of Biological Objects Research Articles

A Large Range of Motion 3D MEMS Scanner With Five Degrees of Freedom

Here, we discuss a novel, mixed mode 3D XYZ scanner built within a single foundry process. The device has a large range of motion in X, Y, and Z ( $14.1~\mu \text{m}$ in X and Y and $97.9~\mu \text{m}$ in Z) and can also rotate about two axes (7.4°), making it a 5 degree of freedom scanner. Vertical actuation can be accomplished with both thermal actuators, which have a larger range of motion, and capacitive actuators, which are faster, responding fully up to 3.2 kHz. Although useful for many applications, including scanning probe microscopy, micrometer scale optical microscopy, and manipulation of biological objects, the device was designed to be a 3D scanner for spray-painting atoms upon a surface with nanoscale precision and resolution for nanofabrication. Demonstrating the ability to combine the device with other complicated MEMS systems, it is integrated with an XY scanner designed to serve as a shutter of atomic flux. The full system has 7 degrees of freedom and 12 actuation motors, and because it is built in a low cost commercial foundry with a robust and stable process, it is easy and inexpensive to fabricate multiple copies or integrate into other complicated systems, making a system of systems. [2018-0213]

Single-cell bacterium identification with a SOI optical microcavity

Photonic crystals and microcavities act as on-chip nano-optical tweezers for identification and manipulation of biological objects. Until now, optical trapping of virus and bacteria has been achieved and their presence in the vicinity of the optical resonator is deduced by the shift in the resonant wavelength. Here, we show trapping and identification of bacteria through a properly tuned silicon on insulator microcavity. Through the spatial and temporal observations of bacteria–cavity interaction, the optical identification of three different kinds of bacteria is demonstrated.

Manipulation of biological objects using acoustic bubbles: a review.

When a bubble oscillates in an acoustically driven pressure field, its oscillations result in an attractive force on micro-sized objects in the near field. At the same time, the objects are subject to a viscous drag force due to the streaming flow that is generated by the oscillating bubble. Based on these secondary effects, oscillating bubbles have recently been implemented in biological applications to control and manipulate micron-sized objects. These objects include live microorganisms, such as Caenorhabditis elegans and Daphnia (water flea), as well as cells and vesicles. Oscillating bubbles are also used in delivering drugs or genes inside human blood vessels. In this review paper, we explain the underlying physical mechanism behind oscillating bubbles and discuss some of their key applications in biology, with the focus on the manipulation of microorganisms and cells.

Characterization and operation of a mechanically actuated silicon microgripper

Since the manipulation of biological objects is usually performed in a life-sustaining environment, electrical fields or thermal gradients through the liquid may cause perturbations. The authors present a microgripper fabricated in silicon by a combination of bulk and surface micromachining processes that exhibits several advantages compared to previous reports. In order to avoid any possible perturbation caused by electrical fields, their microgripper is mechanically actuated. The complete system including the microgripper, a piezoactuator, and a nanomanipulator is described in detail together with manipulation of micrometer sized glass spheres.

Cell manipulation and tissue engineering at the nanoscale

This paper surveys different methods developed for nanoscale spatial manipulation of biological objects and for engineering nanoscale spatial cues to steer cellular biosystems. For the cell manipulation a new electroporation method based on multiwalled carbon nanotubes (MWCNTs) was developed in our group. By applying short microwave (mw) pulses, it was possible to induce dipoles at the MWCNT tips, which in turn can interact with charges at the cell surface. This significantly reduces the cell mortality, compared to conventional electroporation, which is related to the elimination of high electric fields and side reactions. This “nanoelectroporation” approach assisted by MWCNTs allows for rapid transport of metal nanoparticles into bacteria and yeast cells, as well as the incorporation of exogenous DNA into the cell’s genome, without affecting the cell viability and/or morphology. Another field within the scope of bio-nanotechnology is tissue engineering. This form of engineering includes the creation of scaffolds with adjustable pore size distribution and interconnectivity, and the production of micro/nanotopography on the various substrates. Here we present free-standing scaffolds made up of interconnected MWCNTs, which were prepared by chemically induced capillary and tensile forces exerted on the MWCNTs. Their potential application in this field was confirmed by extensive growth, spreading, and adhesion of a common mouse fibroblast cell line.