Georgios Varnavides | Bioelectronics at MIT

Generalized design principles for hydrodynamic electron transport in anisotropic metals

Fri, 12 Aug 2022 00:00:00 +0000

Probing Neuro-Endocrine Interactions Through Remote Magnetothermal Adrenal Stimulation

Thu, 23 Jun 2022 04:52:56 +0000

Probing carrier interactions using electron hydrodynamics

Tue, 12 Apr 2022 00:00:00 +0000

Mesoscopic finite-size effects of unconventional electron transport in PdCoO2

Fri, 08 Apr 2022 15:03:05 +0000

Imaging phonon-mediated hydrodynamic flow in WTe2

Thu, 16 Sep 2021 00:00:00 +0000

Capturing 3D atomic defects and phonon localization at the 2D heterostructure interface

Wed, 15 Sep 2021 00:00:00 +0000

Generalized Design Principles for Hydrodynamic Electron Transport in Anisotropic Materials

Wed, 01 Sep 2021 00:00:00 +0000

Influence of Magnetic Fields on Electrochemical Reactions of Redox Cofactor Solutions

Mon, 07 Jun 2021 00:00:00 +0000

Finite-size effects of electron transport in PdCoO2

Thu, 03 Jun 2021 00:00:00 +0000

Direct Imaging and Electronic Structure Modulation of moiré Superlattices at the 2D/3D Interface

Fri, 26 Feb 2021 00:00:00 +0000

Electron hydrodynamics in anisotropic materials

Fri, 18 Sep 2020 00:00:00 +0000

Mechanical Way to Stimulate Neurons

Sun, 19 Jul 2020 00:00:00 +0000

In addition to responding to electrical and chemical stimuli, many of the body’s neural cells can also respond to mechanical effects, such as pressure or vibration. But these responses have been more difficult for researchers to study, because there has been no easily controllable method for inducing such mechanical stimulation of the cells. Now, researchers at MIT and elsewhere have found a new method for doing just that.

The finding might offer a step toward new kinds of therapeutic treatments, similar to electrically based neurostimulation that has been used to treat Parkinson’s disease and other conditions. Unlike those systems, which require an external wire connection, the new system would be completely contact-free after an initial injection of particles, and could be reactivated at will through an externally applied magnetic field.

The finding is reported in the journal ACS Nano, in a paper by former MIT postdoc Danijela Gregurec, Alexander Senko PhD ’19, Associate Professor Polina Anikeeva, and nine others at MIT, at Boston’s Brigham and Women’s Hospital, and in Spain.

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Magnetothermal Multiplexing for Selective Remote Control of Cell Signaling

Fri, 10 Jul 2020 00:00:00 +0000

Magnetic Nanodiscs Enable Remote Magnetomechanical Neural Stimulation

Fri, 19 Jun 2020 00:00:00 +0000

Magnetic Vortex Nanodiscs Enable Remote Magnetomechanical Neural Stimulation

Fri, 19 Jun 2020 00:00:00 +0000

Hormone Release

Fri, 10 Apr 2020 00:00:00 +0000

Abnormal levels of stress hormones such as adrenaline and cortisol are linked to a variety of mental health disorders, including depression and PTSD. MIT researchers, including the Anikeeva group, have now devised a way to remotely control the release of these hormones from the adrenal gland using magnetic nanoparticles.

To achieve control over hormone release, Dekel Rosenfeld, an MIT-Technion postdoc in Professor Anikeeva’s group, has developed specialized magnetic nanoparticles that can be injected into the adrenal gland. When exposed to a weak magnetic field, the particles heat up slightly, activating heat-responsive channels that trigger hormone release. This technique can be used to stimulate an organ deep in the body with minimal invasiveness.

The researchers now plan to use this approach to study how hormone release affects PTSD and other disorders, and they say that eventually it could be adapted for treating such disorders. This method would offer a much less invasive alternative to potential treatments that involve implanting a medical device to electrically stimulate hormone release, which is not feasible in organs such as the adrenal glands that are soft and highly vascularized.

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Transgene-free remote magnetothermal regulation of adrenal hormones

Wed, 01 Apr 2020 00:00:00 +0000

Nonequilibrium phonon transport across nanoscale interfaces

Tue, 03 Sep 2019 00:00:00 +0000

Remotely controlled chemomagnetic modulation of targeted neural circuits

Mon, 19 Aug 2019 00:00:00 +0000

Artificial Muscle

Fri, 12 Jul 2019 00:00:00 +0000

Strain-programmable fiber-based artificial muscle

Fri, 12 Jul 2019 00:00:00 +0000

Artificial Muscles

Thu, 11 Jul 2019 00:00:00 +0000

MIT researchers, including professors Polina Anikeeva, Yoel Fink, and Cem Tasan, have developed a new fiber-based system that could be used as artificial muscles for robots, prosthetic limbs, or other mechanical and biomedical applications. Inspired by cucumber plants, which use their tightly-coiled tendrils to pull the plants upwards, this system utilizes a heat-activated coiling-and-pulling mechanism. Two materials that have different rates of thermal expansion are joined, causing the resulting fiber to form a tight coil with a surprisingly strong pulling force when even a small increase in temperature is applied. This process of contracting and expanding was shown in testing to maintain its strength even after repeating 10,000 times.

These fibers can span a wide range of sizes, and can easily be manufactured in batches up to hundreds of meters long. They are extremely lightweight and can respond quickly. Such fibers could be useful as actuators in robotic arms, legs, or grippers, as well as in prosthetic limbs, although postdoc Mehmet Kanik says that the possibilities for materials of this type are virtually limitless.

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