Harvard College

Purdue Research Foundation

Shriram Ramanathan

Changhyun Ko

Alexander C Johnson

Dmitry Ruzmetov

You Zhou

Venkatesh Narayanamurti

Jong Hyun Choi

Derek Karl Schwanz

Haitian Zhang

Zheng Yang

Yifei Sun

Changhun Ko

Feiran Li

Yoshitaka Sugita

Zhen Zhang

Jian Shi

Fan Zuo

Disclosed herein is an ultralow concentration sensor of biomarkers, and the use thereof to help heath industry, medical centers and food industry to sense biomarkers by catalyst assisted charge transfer from the biomarkers to the sensor device, resulting increased electrical resistance of the sensor. Specifically, perovskite nickelate RNiOis used to sense biological material facilitated by specific enzymatic activity in the proximity.

Ultralow concentration sensing of bio-matter with perovskite nickelate devices and arrays

A gas sensing device is provided. The gas sensing device includes a substrate, a sensing film deposited on the substrate, and a plurality of electrodes deposited on the sensing film. The sensing film comprising ReNiO3, wherein Re is a rare-earth cation wherein. At least one of the electrodes including platinum, palladium, or a combination thereof. The electrodes are spaced apart from each other for measurement of electrical resistance.

Microstructurally engineered perovskite gas sensor

An electrochromic structure is disclosed, which includes a first transparent non-conductive (GLASS-I) layer, a first transparent conductor (CONDUCTOR-I) layer coupled to the GLASS-I layer, an ion storage layer coupled to the CONDUCTOR-I layer, an electrolyte layer coupled to the ion storage layer, an electrochromic layer coupled to the electrolyte layer, a second transparent conductor (CONDUCTOR-II) layer coupled to the electrochromic layer, and a second transparent non-conductive (GLASS-II) layer coupled to the CONDUCTOR-II layer, wherein the electrochromic layer includes perovskite nickelates thin films formed on a transparent conductive film substrate and which has crystalline grains of the size of about 5 nm to about 200 nm resulting in intergranular porosity of about 5% to about 25%.

Porous perovskite nickelates with enhanced electrochromic properties and systems thereof

An electric field sensing device. The device includes a substrate, a sensing medium capable of experiencing a change in its electrical resistivity in response to an electric field, and electrodes for use in measuring the change. A method of making an electric field sensing device. The method includes depositing on a substrate a sensing medium capable of experiencing a change in its electrical resistivity in response to an electric field emitted by an object; and placing electrodes for use in measuring the change. An electric field sensing system. The system contains a plurality electric field sensing devices, an arrangement of the plurality sensing devices in a way to detect spatial variation of electric field emitted by objects in an environment; a computer system capable of monitoring the sensing devices, and detecting and comparing differences between the electrical fields sensed by individual devices.

Electric field sensing devices and systems and method of making the same

Reversible phase transitions of exceptional magnitude may be induced in correlated metal oxides by altering their chemical compositions through reversible introduction of dopant ions and electronic carriers into the correlated metal oxides. One or more catalyst electrodes may be deposited onto a surface of a film of a correlated metal oxide such as a perovskite or a transition metal oxide. Dopant ions and electronic carriers may be electrochemically introduced into the catalyst-deposited correlated metal oxide, for example by annealing the catalyst-deposited film of correlated metal oxide in a chamber containing the dopant molecules. In this way, a reversible phase transition of about five to eight orders of magnitude may be induced.

Dopant-driven phase transitions in correlated metal oxides

A solid oxide fuel cell has a reinforced membrane-electrode assembly. The solid oxide fuel cell includes a first electrode layer, a second electrode layer, and an electrolyte membrane disposed between the first and second electrode layers. The solid oxide fuel cell further includes a gas-permeable structure adjacent to one or both of the electrode layers, for mechanical stabilization.

Solid oxide fuel cell with reinforced electrolyte membrane

Phase transition devices may include a functional layer made of functional material that can undergo a change in conductance in response to an external stimulus such as an electric or magnetic or optical field, or heat. The functional material transitions between a conducting state and a non-conducting state, upon application of the external stimulus. A capacitive device may include a functional layer between a top electrode and a bottom electrode, and a dielectric layer between the functional layer and the top electrode. A three terminal phase transition switch may include a functional layer, for example a conductive oxide channel, deposited between a source and a drain, and a gate dielectric layer and a gate electrode deposited on the functional layer. An array of phase transition switches and/or capacitive devices may be formed on a substrate, which may be made of inexpensive flexible material.

Phase transition devices and smart capacitive devices

A tunable resistance system includes a layer of a first functional material deposited on a component of the system. The first functional material undergoes a phase transition at a first critical voltage. An insulating layer is deposited upon the layer of first functional material. A layer of a second functional material deposited on the insulating layer. The second functional material undergoes a phase transition at a second critical voltage. The insulating layer is configured to induce a stress on the layer so as to change the first critical voltage. In this way, the resistance of the system is tunable, allowing the system to undergo multi-stage electrical switching of resistive states.

Electrically-driven phase transitions in functional oxide heterostructures

Thin films of vanadium oxide having exceptionally high metal-insulator transition properties are synthesized by RF sputtering. An Al2O3 substrate is placed in a sputtering chamber and heated to a temperature up to about 550 degrees Celsius. Ar and O2 gases are introduced into the sputtering chamber at the flow values of about 92.2 sccm and about 7.8 sccm respectively. A voltage is applied to create a plasma in the chamber. A sputtering gun with vanadium target material is ignited and kept at a power of about 250 W. The phase transition parameters of vanadium dioxide thin films, synthesized by RF sputtering, are modulated by exposing the vanadium dioxide thin film to UV (ultraviolet) radiation so as to induce a change in oxygen incorporation of the vanadium dioxide thin film.

Vanadium oxide thin films

In various aspects, provided are solid oxide fuel cells with an operational temperature of less than about 500&#xb0; C. that can provide, in various embodiments, a power density of greater than about 0.1 W/cmand/or have an ionic conductivity of greater than about 0.00001 ohmcm. In various embodiments, provided are solid oxide fuel cells comprising a solid oxide electrolyte layer that is both an electronic and ionic conductor. In various aspects, provided are methods of making solid oxide fuel cells. In various aspects, provided are solid oxide materials comprising a polycrystalline ceramic layer less than about 100 nm thick having a ionic conductivity of greater than about 0.00001 ohmcmat a temperature less than about 500&#xb0; C.

Micro-scale energy conversion devices and methods

Phase transitions (such as metal-insulator transitions) are induced in oxide structures (such as vanadium oxide thin films) by applying an electric field. The electric field-induced phase transitions are achieved in VOstructures that scale down to nanometer range. In some embodiments, the optical and/or dielectric properties of the oxide structures are actively tuned by controllably varying the applied electric field. Applying a voltage to a single-phase oxide material spontaneously leads to the formation of insulating and conducting regions within the active oxide material. The dimensions and distributions of such regions can be dynamically tuned by varying the applied electric field and/or the temperature. In this way, oxide materials with dynamically tunable optical and/or dielectric properties are created.

Growing community of inventors

Acton, MA, United States of America

Shriram Ramanathan