A system and method for determining tissue changes. Shear waves are transmitted across the tissue in response to an ultrasonic signal input exterior to the tissue surface. Adaptive beam forming signal processing is applied to signal returns and arrivals to remove distortions by targeting velocity contrasts. Shear-wave dispersion, such as due to viscosity and mass changes in the tissue, are then estimated and compared to reference data to determine tissue health.

A fluid sensor includes a housing and a thermal emitter in the housing to emit first thermal radiation into a detection volume of the housing at a first power level during a measurement interval and emit the first thermal radiation at a reduced first power level or not emit said first thermal radiation at all during an intermediate interval disposed outside of the measurement interval. The fluid sensor includes a measuring element in the detection volume to receive a radiation signal during the measurement interval. The fluid sensor includes a second thermal emitter in the housing to emit second thermal radiation at a second power level into the detection volume during the intermediate interval such that a thermal oscillation of thermal radiation in relation to an overall power level of the thermal radiation in the detection volume is at most 50% during the measurement interval and the intermediate interval.

A method of performing atomic force microscopy (AFM) measurements, uses an ultrasound transducer to transmit modulated ultrasound waves with a frequency above one GHz from the ultrasound transducer to a top surface of a sample through the sample from the bottom surface of the sample. Effects of ultrasound wave scattering are detected from vibrations of an AFM cantilever at the top surface of the sample. Before the start of the measurements a drop of a liquid is placed on a top surface of the ultrasound transducer. The sample is placed on the top surface of the ultrasound transducer, whereby the sample presses the liquid in the drop into a layer of the liquid between the top surface of the ultrasound transducer and a bottom surface of the sample. The AFM measurements are started after a thickness of the layer of the liquid has stabilized.

A system and method for measuring characteristics, comprising: a directed energy source having an energy output which changes over time, incident on an object undergoing additive manufacturing; a sensor configured to measure a dynamic thermal response of at least a portion of the object undergoing additive manufacturing proximate to a directed location of the directed energy source over time with respect distance from the directed location; and at least one processor, configured to analyze the measured dynamic thermal response to determine presence of a manufacturing defect in the object undergoing additive manufacturing, before completion of manufacturing.

A transducer system. The system comprises a transducer and circuitry for applying an excitation waveform to excite the transducer during an excitation period. The circuitry for applying has: (i) circuitry for applying a first waveform at a first frequency; and (ii) circuitry for applying a second waveform at a second frequency differing from the first frequency.

Systems and methods of determining physical conditions of a battery, such as state of charge (SOC), state of health (SOH), quality of construction, defect, or failure state include driving two or more acoustic signals of two or more amplitudes, each acoustic signal having two or more frequencies, into the battery and detecting vibrations generated in the battery based on the two or more acoustic signals. Nonlinear response characteristics of the battery for the two or more acoustic signals are determined from the detected vibrations. The physical conditions of the battery are determined based at least in part on the nonlinear response characteristics, using nonlinear acoustic resonance spectroscopy (NARS) or nonlinear resonant ultrasound spectroscopy (NRUS).

An ultrasonic inspection system performs a method of inspecting a layer of a component formed on a build plate using an additive manufacturing process. The inspecting includes delivering to the layer, through the build plate and any intervening layers of the component previously formed on the build plate, an ultrasonic chirp pulse having a frequency that sweeps through a range of frequencies across a chirp bandwidth. The method also includes receiving from the layer ultrasonic energy including reflections of the ultrasonic chirp pulse delivered to the layer, and processing the ultrasonic energy to produce an ultrasonic signature indicative of a characteristic of the layer and the intervening layers. The inspecting is repeated for each of subsequent layers of the component formed on the build plate according to the additive manufacturing process to inspect the component layer-by-layer as the component is built-up during the additive manufacturing process.

A system for detecting cracks in an underwater structure can include an acoustic signal transmitter configured to be disposed proximate to, but without physically contacting, the underwater structure, where the acoustic signal transmitter is configured to emit acoustic signals. The system can also include an acoustic field receiver configured to be disposed proximate to, but without physically contacting, the underwater structure, where the acoustic field receiver is configured to receive resulting acoustic fields. The system can further include a controller that is configured to receive the resulting acoustic fields from the acoustic field receiver. The controller can also be configured to analyze the resulting acoustic fields signal. The controller can further be configured to detect, based on analyzing the resulting acoustic fields, a crack in the underwater structure.

A gas concentration measurement device comprises: a transmission circuit and a transmission oscillator for transmitting first ultrasonic waves in a concentration measurement space and transmitting second ultrasonic waves, which continue temporally from the first ultrasonic waves in the concentration measurement space; a reception oscillator and a reception circuit for receiving the ultrasonic waves that have propagated through the concentration measurement space; and a propagation time measurement unit for determining, on the basis of the times at which the first ultrasonic waves and the second ultrasonic waves were transmitted and the times at which the first ultrasonic waves and the second ultrasonic waves were received, the time in which ultrasonic waves propagate through the concentration measurement space. The second ultrasonic waves have an opposite phase with respect to that of the first ultrasonic waves, and the amplitude of the second ultrasonic waves is greater than that of the first ultrasonic waves.

An electromechanical amplifying method including a transducing an electrical signal to a mechanical resonator having a mechanical resonance mode with an angular frequency .sub.0; transducing the non-linear oscillations of the resonator into a transduced electrical signal; and filtering the transduced electrical signal to obtain an output signal, the signal transduced to the resonator being obtained by adding a first input signal of a first amplitude and a first angular frequency .sub.s and a second pump signal of a second amplitude greater than the first amplitude and of a second angular frequency .sub.s that is different from the first angular frequency, the first and second angular frequencies being close to the angular frequency .sub.0 of the mechanical resonator and the second pump signal being chosen from a range of angular frequencies .sub.p and amplitudes in which the resonator is actuated in a non-linear regime.