Abstract: A charge recycling circuit in an integrated circuit DC-DC converter having two power MOSFETs, the charge recycling circuit comprising a single inductor and recycling MOSFET switches arranged and sized such that when one of the two power MOSFETs is turning off, its gate capacitance charges are transferred to the single inductor, stored in the single inductor and then transferred directly to the gate of the other power MOSFET to turn it on.

Abstract: A method for communicating directly with commodity Wi-Fi transceivers (TRXs) via backscatter modulation in an integrated tag device is provided. The method includes sensing an incident Wi-Fi-compliant wake-up signal. The method than reflects the incident Wi-Fi-complaint wake-up signal by encoding data from the tag device such that the reflected signal follows the Wi-Fi standard compliant and can be decoded by another WiFi-device. An integrated device includes a downlink Wi-Fi compatible wake-up receiver that checks timing of Wi-Fi compatible signals for a wake-up packet. The device has a modulator that is turned on in response to the wake-up packet and a mixer in the modulator hat mixes tag data with a payload packet from received Wi-Fi payload. Backscatter switches backscatter the response.

Abstract: A method for obtaining neural signals from a neural signal sensor includes extracting sensor offset from a neural input signal. Sensor offset is removed from N-channels that share a single amplifier. The neural input signal is acquired from the analog domain by neural electrodes with varying DC-offset and the method includes multiplexing the N-channels via a time divisional multiple access procedure into a single neural amplifier An integrated digitally assisted neural recording system includes an analog multiplexer structured to receive N-channels and to multiplex the N-Channels into a single neural amplifier. A feedback loop is configured to cancel electrode offset voltage in the digital domain by generating electrode offset voltage samples and adding delay to align each electrode offset voltage sample to be subtracted at the neural amplifier in the analog domain.

Abstract: A beam-steering backscatter circuit in an integrated tag device. The circuit includes an antenna array and SP4T reflector array configured to receive and transmit through the antenna array. A baseband phase-shifting module modulates an incident signal based upon tag data to create an output signal and re-radiates the output signal with a controllable angle of direction through the SP4T reflector array. A phase locked loop synchronized with a wake-up receiver provides an intermediate frequency (IF) clock to the baseband phase shifting-module.

Abstract: A method for communicating directly with commodity Wi-Fi transceivers (TRXs) via backscatter modulation in an integrated tag device is provided. The method includes sensing an incident Wi-Fi? compliant wake-up signal. The method than reflects the incident Wi-Fi-complaint wake-up signal by encoding data from the tag device such that the reflected signal follows the Wi-Fi standard compliant and can be decoded by another WiFi-device. An integrated device includes a downlink Wi-Fi compatible wake-up receiver that checks timing of Wi-Fi compatible signals for a wake-up packet. The device has a modulator that is turned on in response to the wake-up packet and a mixer in the modulator hat mixes tag data with a payload packet from received Wi-Fi payload. Backscatter switches backscatter the response.

Abstract: A method for obtaining neural signals from a neural signal sensor includes extracting sensor offset from a neural input signal. Sensor offset is removed from N-channels that share a single amplifier. The neural input signal is acquired from the analog domain by neural electrodes with varying DC-offset and the method includes multiplexing the N-channels via a time divisional multiple access procedure into a single neural amplifier An integrated digitally assisted neural recording system includes an analog multiplexer structured to receive N-channels and to multiplex the N-Channels into a single neural amplifier. A feedback loop is configured to cancel electrode offset voltage in the digital domain by generating electrode offset voltage samples and adding delay to align each electrode offset voltage sample to be subtracted at the neural amplifier in the analog domain.

Abstract: A DC-DC converter for converting an input voltage from a battery source includes a piezoelectric converter and a switched capacitor network between the battery source and the piezoelectric converter. The switched capacitor network provides a flying capacitor configured to be soft-charged and soft discharged due to an inductive operation of the piezoelectric converter such that charge-sharing loss of the flying capacitor is eliminated.

Abstract: A well imaging sensor device includes a sealed housing transparent to ultrasound waves and resistant to downhole pressures. The housing is configured to attach to a downhole equipment piece while allowing the downhole equipment piece to perform its intended function. Components in the housing include a battery, a motor, an ultrasound generator with an angled reflective surface, an ultrasound sensor spaced apart from the ultrasound generator, and ultrasonic amplification medium between the ultrasound generator and the ultrasound sensor. The ultrasound generator is mounted on a mount that rotates in response to the motor and extends through a seal that seals the ultrasound amplification medium away from the battery and the motor.

Abstract: A transmitter for a magnetic body area network includes a power oscillator that directly uses a body coil as a resonant element. Shunt transistor circuitry is between the power oscillator and the body coil, the shunt transistor circuitry selectively shunts current from the body coil in response to a data signal provided to the transmitter. Power injection circuitry is synchronized to the power oscillator to selectively inject power into the body coil in response to the data signal. A tuning capacitor array is disposed to tune frequency in the body coil. A frequency-locked-loop responds to a frequency in the body coil and tunes the tuning capacitor array to lock to a carrier frequency. Very high Q coils can be used while achieving high data transmission rates of 5 mbps to 10 mbps. Transmitters and methods are applicable to on-off-key modulation, frequency-shift modulation and amplitude-shift modulation.

Abstract: A non-invasive epidermal electrochemical sensor device includes an adhesive membrane; a flexible or stretchable substrate disposed over the adhesive membrane; and an anodic electrode assembly disposed over the flexible or stretchable substrate including an iontophoretic electrode. The device includes a cathodic electrode assembly disposed adjacent to the anodic electrode assembly over the flexible or stretchable substrate and includes an iontophoretic electrode. Either the cathodic electrode assembly or the anodic electrode assembly also includes a sensing electrode that includes a working electrode and at least one of a counter electrode or a reference electrode. The iontophoretic electrode in either the anodic electrode assembly or the cathodic electrode assembly that includes the sensing electrode is disposed on the substrate to at least partially encompass the working electrode and the at least one of the counter electrode or the reference electrode.

Abstract: A method for waking a transceiver for communicating directly with commodity Wi-Fi transceivers (TRXs) via backscatter modulation in an integrated tag device includes sensing an incident Wi-Fi-compliant wake-up signal with a wake-up stage. Upon wake-up, a payload packet is sensed with a sync stage, the sync stage having higher bandwidth and power than the wake-up stage, the sync stage enabling a backscatter transmission circuit in sync with the payload. A backscatter transceiver includes a wake-up receiver having an energy-detection based architecture and having circuitry to conduct a counter-based wake up responsive to two pre-specified WiFi compatible packets. A sync receiver is enabled by the wake-up receiver upon reception of the two pre-specified WiFi compatible packets, the sync receiver including circuitry to detect a payload packet and create a backscatter enable signal synced with a payload of the payload packet. A backscatter transmitter is enabled by the backscatter enable signal.

Abstract: A beam-steering backscatter circuit in an integrated tag device. The circuit includes an antenna array and SP4T reflector array configured to receive and transmit through the antenna array. A baseband phase-shifting module modulates an incident signal based upon tag data to create an output signal and re-radiates the output signal with a controllable angle of direction through the SP4T reflector array. A phase locked loop synchronized with a wake-up receiver provides an intermediate frequency (IF) clock to the baseband phase shifting-module.

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: A charge recycling circuit in an integrated circuit DC-DC converter having two power MOSFETs, the charge recycling circuit comprising a single inductor and recycling MOSFET switches arranged and sized such that when one of the two power MOSFETs is turning off, its gate capacitance charges are transferred to the single inductor, stored in the single inductor and then transferred directly to the gate of the other power MOSFET to turn it on.

Abstract: Disclosed are self-powering biofuel cell and sensor devices, systems and techniques. In some aspects, a self-powered biosensing system includes an electronic circuit; an anode including an enzymatic layer electrically coupled to a power supply voltage terminal of the electronic circuit and configured to interact with an analyte in a fluid, such as glucose or lactate; and a cathode electrically coupled to a ground voltage terminal of the electronic circuit, where the electronic circuit is operable to control and use the electrical energy generated at the anode and cathode for powering the biosensing system and detecting a concentration of the analyte in the fluid.

Abstract: A method for communicating directly with commodity Wi-Fi transceivers (TRXs) via backscatter modulation in an integrated tag device is provided. The method includes sensing an incident Wi-Fi?compliant wake-up signal. The method than reflects the incident Wi-Fi- complaint wake-up signal by encoding data from the tag device such that the reflected signal follows the Wi-Fi standard compliant and can be decoded by another WiFi-device. An integrated device includes a downlink Wi-Fi compatible wake-up receiver that checks timing of Wi-Fi compatible signals for a wake-up packet. The device has a modulator that is turned on in response to the wake-up packet and a mixer in the modulator hat mixes tag data with a payload packet from received Wi-Fi payload. Backscatter switches backscatter the response.

Abstract: Disclosed are systems, devices and methods for continuous and simultaneous monitoring of multiple analytes within interstitial fluid by an integrated system for a microneedle array sensor platform. In some aspects, the device includes a microneedle array sensor unit, an electronics unit and a housing structure. The electronics unit is in electrical communication with an array of electrode probe structures via an array of surface-mount, spring loaded pins, and the electronics unit includes a power source, a data processing unit, and a wireless transmitter. The housing structure is configured to encase, at least partially, the microneedle array sensor unit and the electronics unit, where the array of microneedles is exposed from a side of the housing structure. The device can be configured as a patch worn on skin of a patient user.

Abstract: Apparatuses and methods are disclosed for efficient wireless powering of an electrical load with precise external control over pulsed voltage waveform and metering of charge delivered. The system interfaces to an inductive coil for RF power delivery from an external duty-cycled RF power transmitter, and the electrical load. The electrical load may be a photosensitive array of electrodes for an optically addressed, electrically activated retinal prosthesis. The voltage waveform to activate the load is controlled by the transmitted RF amplitude, including switching between cathodic and anodic phases of electrical stimulation. Charge delivered to the load is quantified as discharge events through a series capacitor, transmitted by backtelemetry to the receiver for continuous monitoring throughout the stimulation phases.

Abstract: A low-power wake-up receiver includes a mixer-based two-stage heterodyne architecture that provides multi-stage channel filtering, including a combination of circuits and a digital signal processor that process energy in a plurality of advertising channels to detect a four-dimensional wake-up signature via frequency-hopping among the plurality of advertising channels. One receiver is a BLE/Wi-Fi dual-mode wake-up receiver.

Abstract: A charging to digital converter sensor in a CMOS integrated circuit digitizes a sensed property by comparing charging time between two paths and adjusting the charging rate of one of the two paths by increasing or decreasing the amount of capacitance in that path, until both of the two paths have the same charging time to reach respective constant with sensed property and proportional with sensed property reference voltages or currents. Sub nanowatt operation is achieved with preferred circuits. A method directly digitizes, on-chip, a charging time comparison of two ramp voltages that are compared to respective constant with sensed property and proportional with sensed property reference voltages or currents.