Abstract: Methods, systems, and devices are disclosed for providing test strip electrochemical sensors for rapid quantitative analysis of analytes in physiological fluids. In one aspect, an electrochemical sensor includes a substrate; an electrode contingent including a first electrode having a coating of carbon nanotubes (CNTs) and a second electrode on the substrate; and an entrapment layer formed on the first electrode to attach an enzymatic substance capable of causing a redox reaction in the presence of a target analyte of a fluid sample which produces a redox-active product, in which the entrapment layer is structured to include a conductive polymer film that is reversibly dopable to conduct charge carriers across the entrapment layer and at the first electrode. For example, the electrochemical sensor can be provided on a disposable test strip to quantify L-DOPA levels in whole blood, plasma, or serum samples.

Abstract: Techniques, devices and systems are disclosed for implementing acoustically triggered propulsion of nano- and micro-scale structures. In one aspect, an ultrasound responsive propulsion device includes a tube that includes one or more layers including an inner layer having an electrostatic surface, and an ultrasound-responsive substance coupled to the inner layer and configured to form gaseous bubbles in a fluid in response to an ultrasound pulse, in which the bubbles exit the tube to propel the tube to move in the fluid.

Abstract: A method and system are provided for detection of localized hydrogen peroxide within tissue by introducing a catalase-containing material into at location of interest, positioning an ultrasound transducer over the location, and generating an ultrasound image to detect microbubbles, where the presence of microbubbles indicate the presence of localized hydrogen peroxide. The catalase-coated surface may be the inner surface of a microtube, on the surface of or incorporated within a nanosphere or microsphere, or an implantable device.

Abstract: Techniques and systems are disclosed for locomoting fuel-free nanomotors in a fluid. In one aspect of the disclosed technology, a system for locomoting fuel-free nanomotors can include an electrically-driven nanowire diode formed of two or more segments of different electrically conducting materials, a fluid container, and a mechanism that produces an electric field to drive the nanowire diode to locomote in the fluid. In another aspect, a system for locomoting fuel-free nanomotors can include a magnetically-propelled multi-segment nanowire motor formed of a magnetic segment and a flexible joint segment, a fluid container, and a mechanism that generates and controls a magnetic field to drive the multi-segment nanowire motor to locomote in the fluid. The disclosed fuel-free nanomotors can obviate fuel requirements and can be implemented for practical in vitro and in vivo biomedical applications.

Abstract: Methods, systems, and devices are disclosed for the identification of chemical agents and determination of their level of exposure using electrochemical detection and advanced signal processing. In one aspect, a method includes collecting a sample from a surface containing a chemical agent to an electrode on a sensor such that the chemical agent transfers on the electrode, detecting an electrochemical signal of the chemical agent on the electrode to transduce chemical information associated with the chemical agent to an electrical signal, processing the electrical signal to obtain electrochemical spectral signature data to identify the chemical agent and generating a series of coefficients of the electrochemical spectral signature data to reduce the data, and classifying the chemical information based on the series of coefficients among preselected data sets to determine a level of exposure to the chemical agent.

Abstract: Living cells, such as red blood cells (RBCs) modified with functional micromotors with the aid of ultrasound propulsion and magnetic guidance. Iron oxide nanoparticles are loaded into the RBCs, where their asymmetric distribution within the cells results in a net magnetization, thus enabling magnetic alignment and guidance under acoustic propulsion. The RBC motors display efficient guided and prolonged propulsion in various biological fluids, including undiluted whole blood.

Abstract: Methods, structures, devices and systems are disclosed for fabrication of microtube engines using membrane template electrodeposition. Such nanomotors operate based on bubble-induced propulsion in biological fluids and salt-rich environments. In one aspect, fabricating microengines includes depositing a polymer layer on a membrane template, depositing a conductive metal layer on the polymer layer, and dissolving the membrane template to release the multilayer microtubes.

Abstract: Methods, systems, and devices are disclosed mouth-based biosensors and biofuel cells. In one aspect, an electrochemical sensor device for detecting analytes in saliva includes a substrate including an electrically insulative material, a first electrode disposed on the substrate at a first location, in which the first electrode includes a surface including a chemical agent (e.g., a catalyst or a reactant) corresponding to an analyte in saliva; and a second electrode disposed on the substrate at a second location separated from the first electrode by a spacing region, the first and second electrodes capable of sustaining a redox reaction involving the chemical agent and the analyte to produce an electrical signal, such that, when the device is present in the mouth of a user and electrically coupled to an electrical circuit, the device is operable to detect the analyte in the user's saliva.

Abstract: Methods, systems, and devices are disclosed for implementing a biofuel cell device for extracting energy from a biofuel. In one aspect, a biofuel cell device includes a substrate, an anode including a catalyst to facilitate the conversion of a fuel in a biological fluid in an oxidative process that releases electrons captured at the anode, thereby extracting energy from the fuel substance, a cathode configured on the substrate adjacent to the anode and separated from the anode by a spacing region, and a load electrically coupled to the anode and cathode via electrical interconnects to obtain the extracted energy as electrical energy.

Abstract: Disclosed are novel electrolytes, and techniques for making and devices using such electrolytes, which are based on compressed gas solvents. Unlike conventional electrolytes, disclosed electrolytes are based on “compressed gas solvents” mixed with various salts, referred to as “compressed gas electrolytes.” Various embodiments of a compressed gas solvent includes a material that is in a gas phase and has a vapor pressure above an atmospheric pressure at a room temperature. The disclosed compressed gas electrolytes can have wide electrochemical potential windows, high conductivity, low temperature capability and/or high pressure solvent properties.

Abstract: Among other things, methods, systems and apparatus are described for implementing nanomotor-based micro- and nanofabrication. In one aspect, a method of fabricating nanoobjects comprises functionalizing a nanomotor with a reagent. The method also includes controlling a movement of the functionalized nanomotor in a solution containing material to react with the reagent to induce a localized deposition or precipitation of a product onto a surface of a substrate or etching of the substrate.

Abstract: Methods, structures, devices and systems are disclosed for fabrication of microtube engines using membrane template electrodeposition. Such nanomotors operate based on bubble-induced propulsion in biological fluids and salt-rich environments. In one aspect, fabricating microengines includes depositing a polymer layer on a membrane template, depositing a conductive metal layer on the polymer layer, and dissolving the membrane template to release the multilayer microtubes.

Abstract: Techniques and systems are disclosed for implementing textile-based screen-printed amperometric or potentiometric sensors. The chemical sensor can include carbon based electrodes to detect at least one of NADH, hydrogen peroxide, potassium ferrocyanide, TNT or DNT, in liquid or vapor phase. In one application, underwater presence of chemicals such as heavy metals and explosives is detected using the textile-based sensors.

Abstract: Methods, structures, and systems are disclosed for biosensing and drug delivery techniques. In one aspect, a device for detecting an analyte and/or releasing a biochemical into a biological fluid can include an array of hollowed needles, in which each needle includes a protruded needle structure including an exterior wall forming a hollow interior and an opening at a terminal end of the protruded needle structure that exposes the hollow interior, and a probe inside the exterior wall to interact with one or more chemical or biological substances that come in contact with the probe via the opening to produce a probe sensing signal, and an array of wires that are coupled to probes of the array of hollowed needles, respectively, each wire being electrically conductive to transmit the probe sensing signal produced by a respective probe.

Abstract: Methods, systems, and devices are disclosed for the identification of chemical agents and determination of their level of exposure using electrochemical detection and advanced signal processing. In one aspect, a method includes collecting a sample from a surface containing a chemical agent to an electrode on a sensor such that the chemical agent transfers on the electrode, detecting an electrochemical signal of the chemical agent on the electrode to transduce chemical information associated with the chemical agent to an electrical signal, processing the electrical signal to obtain electrochemical spectral signature data to identify the chemical agent and generating a series of coefficients of the electrochemical spectral signature data to reduce the data, and classifying the chemical information based on the series of coefficients among preselected data sets to determine a level of exposure to the chemical agent.

Abstract: A toilet seat includes a fixing member having a first engagement portion and a first pivotal portion. The first engagement is mounted to a toilet bowl. A first seat includes a second pivotal portion and a third pivotal portion respectively on two ends of the first seat. The second pivotal portion is pivotably connected to the first pivotal portion of the fixing member. A second seat includes a fourth pivotal portion pivotably connected to the third pivotal portion of the first seat. A lifting device is connected to the first seat and the second seat. The lifting device is coupled to a controller. The controller is operable to actuate the lifting device to increase or reduce a spacing between the first seat and the second seat.

Abstract: Techniques and systems are disclosed for implementing textile-based screen-printed amperometric or potentiometric sensors. The chemical sensor can include carbon based electrodes to detect at least one of NADH, hydrogen peroxide, potassium ferrocyanide, TNT or DNT, in liquid or vapor phase. In one application, underwater presence of chemicals such as heavy metals and explosives is detected using the textile-based sensors.

Abstract: A method and system are provided for detection of localized hydrogen peroxide within tissue by introducing a catalase-containing material into at location of interest, positioning an ultrasound transducer over the location, and generating an ultrasound image to detect microbubbles, where the presence of microbubbles indicate the presence of localized hydrogen peroxide. The catalase-coated surface may be the inner surface of a microtube, on the surface of or incorporated within a nanosphere or micro sphere, or an implantable device.

Abstract: Methods, structures, devices and systems are disclosed for fabricating and implementing electrochemical biosensors and chemical sensors. In one aspect, a method of producing an epidermal biosensor includes forming an electrode pattern onto a coated surface of a paper-based substrate to form an electrochemical sensor, the electrode pattern including an electrically conductive material and an electrically insulative material configured in a particular design layout, and attaching an adhesive sheet on a surface of the electrochemical sensor having the electrode pattern, the adhesive sheet capable of adhering to skin or a wearable item, in which the electrochemical sensor, when attached to the skin or the wearable item, is operable to detect chemical analytes within an external environment.