Library · Signals, sensing & imaging
What Surface Acoustic Wave Sensing got wrong, from 14 theses
Summary written by a model from the records below: The evaluated records describe experimental and modeling challenges encountered in acoustic wave devices, transducers, and sensors. Documented issues include thermal damage under high drive levels, optical detection limits, acoustic confinement loss, temperature drift, homogenization failures, and acoustic signal distortion. These records come from graduate theses, 2021 to 2025, each labeled with its degree where the repository states it, and each links to its thesis. They were extracted by language models reading the full text, so treat each as a lead to read, not a verdict.
Plus 8 problems the authors left open, listed at the end.
Failure modes, by theses reporting them
Select a mode to jump to its records.
High drive power causes thermal failure and resonance detuning in acoustic devices
Continuous acoustic wave actuation and high driving power led to severe heating, efficiency loss, and permanent transducer damage. In acoustic trap systems, high driving gains caused thermal drift that detuned fluid acoustic resonances and degraded spectra.
Considered and rejected
Considered and rejected: Unstabilized acoustic trap operation at high piezoelectric driving gains (>50% / >14 Vpp): rejected due to thermal drift hampering IR spectra and detuning fluid acoustic resonance.
Tried and failed
continuous high-power acoustic wave actuation without pulsing applied to acoustofluidic microchips with interdigital transducers. Outcome: unstable. Reason: rapid heat accumulation caused thermal failure and permanent interdigital transducer damage within one second
The Versatility and Applicability of Droplet Microfluidics · Harvard · PhD
Tried and failed
high-power acoustic driving of piezoelectric thin-film resonators applied to strain-driven spin control in solid-state devices. Outcome: unstable. Reason: thermal heating and thin-film damage at high input power caused severe non-linear driving efficiency falloff
DESIGNING HIGH SENSITIVITY NUCLEAR INERTIAL SENSORS IN DIAMOND · Cornell · PhD
Optical sensing techniques exhibit insufficient sensitivity to detect low amplitude acoustic waves
Optical streak imaging and point-probe interferometry failed to resolve small-amplitude acoustic waves and nonlinear distortion due to weak refractive index modulation and short propagation paths. Fiber Bragg grating sensors were similarly unable to detect dynamic strain waves even under high actuation voltages.
Tried and failed
optical streak imaging applied to small amplitude acoustic waves in water. Outcome: no signal. Reason: insufficient refractive index modulation produced by low pressure waves in water
Materials At Extremes: Shock-induced Fracture and Phase Transitions · MIT · PhD
Tried and failed
fiber Bragg grating strain sensing applied to guided acoustic wave detection. Outcome: no signal. Reason: insufficient sensitivity to low-amplitude dynamic strain waves even under high actuation voltage
Condition monitoring of composite structure with Fibre Optic Sensors · Imperial · PhD
Tried and failed
point-probe optical interferometry applied to detecting acoustic wave nonlinear distortion. Outcome: no signal. Reason: insufficient sensitivity over short propagation distances limited to hundreds of microns
Weak Shock Waves on a Chip: Generation and Applications · MIT · PhD
Substrate clamping and dimensional constraints suppress acoustic wave excitation and transmission
Substrate clamping prevented surface acoustic wave generation in thin piezoelectric films below submicron thickness thresholds. In addition, acoustic waveguides and resonators experienced high propagation losses and poor energy trapping from surface roughness, modal mismatch, or crystal thickness dimensions.
Tried and failed
surface acoustic wave generation on thin piezoelectric films applied to substrate-bound submicron piezoelectric films. Outcome: no signal. Reason: Mechanical substrate clamping suppressed acoustic wave excitation when film thickness was below 300 nm
Remote Epitaxy by In-Situ Grown BN and InGaN Strain Relaxation · MIT · PhD
Considered and rejected
Considered and rejected: Rejected using the fundamental harmonic (n=1) for liquid droplet surface area analysis due to insufficient energy trapping and acoustic wavelength (~200 μm) being comparable to quartz crystal thickness (~300 μm).
Ultrasonic Shear Wave Spectroscopy for Real-Time Monitoring of Static and Dynamic Liquid-Solid Interfaces · University College Dublin · PhD
Lost to a baseline
Suspended AlN-on-diamond acoustic waveguides exhibited higher loss (-50 dB transmission) compared to ridge acoustic waveguides (-22.4 dB transmission) due to modal mismatch and bottom surface roughness from quasi-isotropic etching.
High-Performance Photonic and Acoustic Interfaces for Qubits · Harvard · PhD
Temperature drift and coefficient mismatch degrade piezoelectric and resonant sensor readouts
Resonant sensor measurements suffered large uncompensated frequency drift when differential resonators had mismatched temperature coefficients. Similarly, piezoelectric sensors were rejected for load weight estimation because of temperature-dependent drift and charge leakage.
Tried and failed
differential frequency readout for temperature compensation applied to resonant sensor measurements. Outcome: unstable. Reason: temperature coefficient mismatches between differential resonators caused large uncompensated frequency drift
ADVANCED FREQUENCY OUTPUT RESONANT MEMS ACCELEROMETERS · Georgia Tech · PhD
Short wavelength surface wave excitation violates homogenization modeling assumptions
Multiscale homogenization asymptotic modeling failed when applied to low-loss resonant metasurfaces because surface wave excitation violated scale separation. Homogenized surface impedance boundary conditions broke down under the same conditions due to violations of subwavelength assumptions.
Tried and failed
multiscale homogenisation asymptotic modeling applied to low-loss resonant metasurfaces. Reason: short-wavelength surface wave excitation near resonance violates scale separation assumptions
Asymptotic models of acoustic resonators and Leidenfrost flows · Imperial · PhD
Tried and failed
homogenised surface impedance boundary conditions applied to resonant metasurfaces under low loss. Outcome: did not generalise. Reason: near-resonance excitation of short-wavelength surface waves violates subwavelength homogenization assumptions
Asymptotic modelling of thermoviscous dissipation in resonant acoustic structures · Imperial · PhD
Acoustic waveform distortion and feature ambiguity prevent reliable measurement correlation
Standard acoustic emission features failed to show clear correlation with sensor sensitivity variations in composite laminates. Envelope detection of active acoustic wave transmissions also showed poor correlation with biological tissue loading due to phase sensitivity and waveform distortion.
Tried and failed
evaluating sensor sensitivity using acoustic emission parameters applied to piezoelectric sensor placement in composite laminates. Outcome: no signal. Reason: standard acoustic emission features showed no clear correlation to sensor sensitivity differences
Performance evaluation of thin acoustic emission sensors in a laminated composite for structural health monitoring · Cranfield · PhD
Tried and failed
continuous active acoustic wave transmission and envelope detection applied to dynamic biological tissue load estimation. Outcome: no signal. Reason: phase sensitivity and waveform distortion caused poor correlation with ground-truth dynamic loading
Machine Learning and Biomechanical Sensing Toward Real-Time In-The-Loop Gait and Joint Health Optimization · Georgia Tech · PhD
Left open by the authors
Problems the authors named and did not get to.
Left open
Evaluate the sensitivity of embedded versus surface-mounted acoustic emission sensors across varying composite laminate thicknesses. Blocker: Requires fabricating composite laminates of varying thickness with embedded piezoelectric sensors and conducting physical acoustic emission testing
Performance evaluation of thin acoustic emission sensors in a laminated composite for structural health monitoring · Cranfield · PhD
Left open
Identify sources of discrepancy between SRAS and bulk experimental surface acoustic wave velocity measurements in Ti-5Al-5Mo-5V-3Cr samples. Blocker: Requires physical ultrasonic testing equipment, SRAS experimental setup, and specific alloy samples
Ultrasonic characterization of Ti-5Al-5Mo-5V-3Cr · Iowa State · Master's
Left open
Measure graphene longitudinal conductivity using high-frequency SAW resonators to identify the crossover from Dirac to Schrödinger-like behavior. Blocker: Requires experimental fabrication and high-frequency surface acoustic wave (SAW) measurement apparatus
Magnetoresistance and surface acoustic waves measurements of quantum materials · Cornell · PhD
Left open
Develop nonreciprocal surface acoustic wave (SAW) devices utilizing nonlinearity and investigate topological characteristics of unidirectional SAW devices. Blocker: Requires a physical acoustics/electronics fabrication and testing laboratory to build and test SAW devices.
Broken passivity and time-reversal-symmetry bounds in acoustics devices · UT Austin · PhD
Left open
Apply the continuous-wave surface acoustic wave dressed-state protocol to negatively charged tin vacancy centers in diamond to decouple spins from magnetic noise. Blocker: Requires diamond samples containing SnV centers, piezoelectric transducer fabrication, cryogenic apparatus, and microwave/SAW experimental laboratory hardware.
Preserving Information in Quantum Systems via Coherent Driving · Harvard · PhD
Left open
Fabricate bulk acoustic wave resonators using strontium titanate (STO) instead of ZnO via pulsed laser deposition to reduce high-frequency loss tangent. Blocker: Requires a physical materials synthesis and nanofabrication lab with pulsed laser deposition equipment.
Fabrication of bulk acoustic wave resonators with ultra-thin graphene electrodes for microwave applications · Imperial · PhD
Left open
Investigate the role of surface-skimming longitudinal waves and the mechanism of surface acoustic wave-induced melting in metals at low shock stresses. Blocker: Requires specialized ultrafast picosecond laser apparatus and shock wave optical setups.
Materials At Extremes: Shock-induced Fracture and Phase Transitions · MIT · PhD
Left open
Investigate why acoustic power transfer improvement is negligible below 39 kHz when piezoelectric transducer reactance is inductive. Blocker: Requires a physical experimental ultrasonic power transfer testbed with specific piezoelectric transducers (FUS-40E)
Acoustic power distribution techniques for wireless sensor networks · Imperial · Doctorate
Who has worked on this
Authors of the public theses cited on this page, most-cited first.
- Jet Lem · MIT · PhD · 2023
Materials At Extremes: Shock-induced Fracture and Phase Transitions - Noor Salam Ghadarah · Cranfield · PhD · 2023
Performance evaluation of thin acoustic emission sensors in a laminated composite for structural health monitoring - Eliza Cornell · Harvard · PhD · 2026
Preserving Information in Quantum Systems via Coherent Driving - Luis G. Rosa · Georgia Tech · PhD · 2025
Machine Learning and Biomechanical Sensing Toward Real-Time In-The-Loop Gait and Joint Health Optimization - Ryan Thomas Garry · Harvard · PhD · 2025
The Versatility and Applicability of Droplet Microfluidics - Weiyi Ding · Harvard · PhD · 2025
High-Performance Photonic and Acoustic Interfaces for Qubits - Jude Deschamps · MIT · PhD · 2025
Weak Shock Waves on a Chip: Generation and Applications - Ioanna Bampouri · University College Dublin · PhD · 2025
Ultrasonic Shear Wave Spectroscopy for Real-Time Monitoring of Static and Dynamic Liquid-Solid Interfaces - Johnathan Kuan · Cornell · PhD · 2024
DESIGNING HIGH SENSITIVITY NUCLEAR INERTIAL SENSORS IN DIAMOND - Jacob Holley · Imperial · PhD · 2024
Asymptotic modelling of thermoviscous dissipation in resonant acoustic structures - Yuxuan Wang · Imperial · PhD · 2024
Fabrication of bulk acoustic wave resonators with ultra-thin graphene electrodes for microwave applications - Yunpeng Liu · MIT · PhD · 2024
Remote Epitaxy by In-Situ Grown BN and InGaN Strain Relaxation
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