University of California

Sheng Xu

Yang Li

Yusheng Lei

Yimu Chen

Chonghe Wang

Hongjie Hu

Xiaoshi Li

Muyang Lin

Lin Zhang

Zhuorui Zhang

Xiaoxiang Gao

Baiyan Qi

In accordance with a method of forming a halide perovskite thin film, a first halide perovskite material is chosen from which a halide perovskite thin film is to be formed. An epitaxial substrate formed from a second halide perovskite material is also chosen. The halide perovskite thin film is epitaxially formed on the substrate from the first halide perovskite material. The substrate is chosen such that the halide perovskite thin film formed on the substrate has a selected value of at least one property. The property is selected from the group including crystal structure stability, charge carrier mobility and band gap.

Strain engineering and epitaxial stabilization of halide perovskites

A method of fabricating an ionic crystal includes providing a single crystal substrate of an ionic crystal material is provided. A patterned mask is applied over the single crystal substrate A growth solution is introduced over the single crystal substrate. The growth solution includes precursors for epitaxial growth of the ionic crystal material on the single crystal substrate such that epitaxial crystals grow over time through pattern openings in the patterned mask into a crystal structure with one or more morphologies.

Fabrication process for flexible single-crystal perovskite devices

A method for monitoring a patient using an ultrasonic probe includes attaching a conformable two-dimensional piezoelectric transducer array having a plurality of phased array piezoelectric transducer elements on an epidermal surface of a patient so that the conformable two-dimensional piezoelectric transducer array conforms to a shape of the epidermal surface. The conformable two-dimensional piezoelectric transducer array is attachable to the epidermal surface by van der Waals forces alone. The plurality of phased array piezoelectric transducer elements is operated as a phased array to transmit a focused ultrasonic beam to a specified location in the patient to be monitored. Ultrasound waves are received from the patient using the array. An indication of the received ultrasound waves is displayed.

System and method for continuous non-invasive ultrasonic monitoring of blood vessels and central organs

A conformable piezoelectric transducer array for performing ultrasound or the like includes a silicone elastomer substrate and a silicone elastomer superstrate. A plurality of piezoelectric transducer elements are disposed between the substrate and superstrate. A first electrical interconnect layer electrically interconnects a first surface of the transducer elements adjacent to the substrate and a second electrical interconnect layer electrically interconnecting a second surface of the transducer elements adjacent to the superstrate.

Stretchable ultrasonic transducer devices

A method for determining mechanical properties of tissue in an individual includes attaching a stretchable and/or flexible ultrasound imaging device to the individual. The imaging device includes at least a one-dimensional array of transducer elements that transmit ultrasound waves into the individual. A first series of ultrasound waves are received from the tissue in the individual before applying a strain to the tissue by compression and a second series of ultrasound waves are received from the tissue after applying the compression to the tissue. Data from the first and second series of ultrasound waves are compared to obtain displacement data of the tissue from which strain data representing strain applied to the tissue is obtainable. A 2D image representing a 2D modulus distribution within the tissue is generated using the displacement data. One or more mechanical properties of the tissue is identified based on the 2D modulus distribution.

Three-dimensional mapping of deep tissue modulus by stretchable ultrasonic arrays

A closed-loop wearable device or platform integrates sensors, actuators, and microcontroller on board. The device is applied directly to the skin using stretchable epidermal electronics. It can sense a variety of signals from the human body, thus collecting medically relevant information, and can activate delivery of a therapeutic upon detection of an abnormal condition. The therapeutic can be delivered at a personalized dosage and/or with a unique combination of drugs or other agents based on the individual's metabolism as tracked by various sensor modules integrated with the medical device.

Closed-loop actuating and sensing epidermal systems

Organic-inorganic hybrid perovskite has demonstrated tremendous potential for the next generation of electronic and optoelectronic devices due to their remarkable carrier dynamics. However, current studies of electronic and optoelectronic devices have been focused on polycrystalline materials, due to the challenges in synthesizing device compatible high quality single crystalline materials. Here, we firstly report the epitaxial growth of single crystal hybrid perovskites with controlled locations, morphologies, and orientations, using combined strategies of lithography, homoepitaxy, and low temperature solution method. The crystals grow following a layer-by-layer model under controlled growth parameters. The process is robust and can be readily scaled up. The as-grown epitaxial single crystals were integrated in an array of light emitting diodes, each crystal as a pixel with enhanced quantum efficiencies. This capability opens up new opportunities for designing and fabricating a diverse range of high performance electronic and optoelectronic devices using crystalline hybrid perovskites.

Controlled homo-epitaxial growth of hybrid perovskites

A method of fabricating a stretchable and flexible electronic device includes forming each of the functional layers is by: (i) forming on an elastomer substrate a conductive interconnect pattern having islands interconnected by bridges; (ii) applying a conductive paste to the islands; (iii) positioning at least one functional electronic component on each island; and (iv) applying heat to cause the conductive paste to reflow. An elastomer encapsulant is formed over the functional electronic components and the conductive interconnect pattern on each of the functional layers. The elastomer encapsulant has a Young's modulus equal to or less than that of the substrate. The encapsulant includes a pigment to increase absorption of laser light. At least one via is laser ablated, which provides electrical connection to any two functional layers. The via is filled with solder paste to create a bond and electrical connection between the functional layers.

Growing community of inventors

La Jolla, CA, United States of America

Sheng Xu