Micro & Nanotech

Micro & Nanotech Portfolios

Most Recent Inventions

Photoreceptor Scaffold for In Vitro Modeling and Transplantation Therapy

Using state-of-the-art microfabrication techniques, UW–Madison researchers have developed microstructured scaffold systems that can guide the growth of photoreceptor cells and mimic polarized outer retinal tissue. The scaffolds also may be used for transplantation of organized photoreceptor tissue with or without RPE.

Transplantation of photoreceptor-seeded scaffolds may improve grafted cell retention, survival, integration and functional visual rescue as compared to simple bolus injections. By recapitulating in vivo outer retinal architecture, these uniquely fabricated scaffolds also can be used for in vitro developmental and disease studies as well as drug screening.

The microfabrication process for scaffold production is fully compatible with numerous biomaterials, including biodegradable and non-biodegradable materials, thus allowing the scaffolds to be tailored to both in vitro and in vivo applications. The scaffolds feature biocompatible support layers (e.g., PDMS film) patterned with an array of unique through-holes having a curvilinear cell receiver and cell guide channels. The structure enables photoreceptors to be grown in a polarized orientation that mimics their development in vivo.

Streamlined Design for Transferring Analytes

The researchers have now improved their design and developed a microfluidic device that directly integrates with tubes, strip tubes and well plates. In this way a sample can be directly transferred from the device to downstream analysis instruments.

The device comprises a strip of wells that hold various volumes of output fluid. Following sample isolation via the researchers’ previously developed SLIDE technique, the strip containing the sample and output buffer is removed from the SLIDE and applied to a set of strip tubes in the same way that conventional covers would be applied.

Then, by flicking or centrifuging the tubes, the sample is transferred from the cap to the tube. At this point the sample is ready for PCR or other downstream analysis.

Circulating Tumor Cell Assay Using Simple Blood Draw

The researchers now have developed the first fully integrated CTC assay that could eliminate the need for painful biopsies. The device leverages verIFAST technology to capture, purify and molecularly analyze CTCs from a single blood sample.

The sample is deposited in a first well and then magnetically drawn through a second well containing an isolation buffer like oil or wax. The increasingly purified cells are drawn into a final well for extraction or further treatment.

The device includes new technical features and is combined with downstream techniques for staining rare cells like CTCs.

Device Uses Air Gap for Easier Fraction Isolation

UW–Madison researchers have developed a new device for isolating desired fractions from a biological sample. The device is made of two plates separated by a gap. The first plate has droplets of bound sample/PMPs positioned on the surface. A second plate containing another reagent is positioned below. A magnet pulls the PMP/sample from the first plate, through the air gap, onto the second plate.

Smoother Surfaces with Pulsed Laser Polishing

UW–Madison researchers have developed a two-regime method to reduce rough surface features using a multiple-pass PLP approach.

In the first regime, melt pools are created on the surface using energy pulses, which generate higher temperatures where the beam is focused. Thermocapillary flow pulls down asperities into the melt pools. This can cause material to push up at the edge of the pools as they resolidify. A second regime applies different energy pulses to remove and/or rearrange the upwelled material.

Most Recent Patents

Handheld Cell Maintenance and Assay Device with Functional Microfluidic Lid

UW–Madison researchers have developed a new design for the handling, freezing, thawing and subsequent study of microliter volumes of cell suspensions. Requiring no additional equipment and adaptable to a wide range of conditions, the device is inexpensive to manufacture and preserves the integrity of cells for research.

The platform employs a functionalized lid, enclosed by a microporous membrane and comprising multiple reservoirs into which cell suspensions are loaded. The addition of cryopreservation fluid permits storage. Another flexible membrane encloses the lid’s bottom side and contains a pinhole. Protective tape seals the reservoirs for shipping and containment.

An assay can be performed readily by peeling away the tape on the top side and placing the device in a thawing bath that removes the preservation fluid via dialysis. The tape on the underside then is taken off and pressure on the pinhole membrane dispenses the fluid into another microfluidic platform containing the specific test components.

Improved Infrared-Responsive Hydrogel for Use in Microfluidics and Optics

UW–Madison researchers have developed an improved infrared-responsive hydrogel by incorporating graphene oxide flakes into a thermo-responsive hydrogel polymer. These composite hydrogels have an intrinsically higher surface area and absorbance band than conventional metal nanoparticles, resulting in a larger volumetric change in response to infrared light. The researchers also have provided a microfluidic device and a lens structure that incorporate these composite hydrogels as actuators. Both devices can be operated by heating the composite hydrogel in its swollen state to a temperature sufficient enough to shrink its volume. The hydrogel can be restored to its original volume by allowing it to cool and re-swell. In the microfluidic device volume reduction of the hydrogel allows fluid to flow through a channel and in the lens structure volume change relates to a change in focal length. 

Snap-On Microfluidic Lid for Handheld Diagnostics and Chemical Tests

UW–Madison researchers have developed a microfluidic design and method that supports rapid and simplified handheld diagnostics and assays.

The device is formed in two separate sections— a base and a functionalized lid—that can be snapped together. The base has channels running between two ports. The lid, which is disposable and holds a well prepackaged with selected liquids like a drug or chemical, has a piercing mechanism. When pressed to the base, the membrane covering the well is perforated and the substance induced to flow down into the base, through its channels and back up into the lid’s absorption pad.

The functionalized lid can not only pump, but also can be designed to apply a chemical gradient using wells filled with hydrogel and reagents that diffuse into the channels.