Engineering seminars

A semiconductor fabrication case study follows a defect from its initial discovery to a potential root cause. The speakers use wafer maps and graphical exploration to identify patterns, connect manufacturing-process and test measurements, and investigate trends across large datasets. The presentation shows how combining these data can narrow the possible causes of defects or changing yield. Drawing on the speakers’ semiconductor-industry experience, it addresses practical troubleshooting for process, yield, research, test and metrology teams and explains how visual analysis can make complex manufacturing data more useful.

Adriana Milic examines how the ATLAS liquid-argon calorimeter supports rapid event selection. After introducing its readout architecture, she explains the Phase-I change from analogue triggering to finely segmented digital Super Cells. Increased granularity, precision and dynamic range enable better background rejection during high-pile-up Run 3 collisions. Finer segmentation also changes signal-to-noise behaviour and the efficiency for low-energy deposits, creating distinct challenges in heavy-ion data taking. The seminar then considers Phase-II plans for greater bandwidth and full-calorimeter information, enabling more sophisticated selection under the conditions expected at the High-Luminosity LHC.

Stephanie Gil studies reliable coordination in robot networks facing malicious information and ordinary environmental uncertainty. Communication signals provide physical evidence of trustworthiness that is difficult to forge; the cy-trust framework turns that evidence into probabilistic trust estimates and weights neighboring agents accordingly. For consensus and distributed optimization, the analysis establishes almost-sure convergence with bounded departures from nominal performance even when malicious agents form a majority of a node’s neighbors, exceeding the classical Byzantine threshold. Theory and hardware experiments support these guarantees. For natural uncertainty, real-time sensing is incorporated into rollout-based reinforcement learning, reweighting possible futures. Applications include fleet routing under random demand and Project CETI’s autonomous robotic rendezvous with sperm whales at sea. The talk closes with directions for combining trust and long-horizon sequential decisions to retain resilience when planning data may be corrupted.

This practical presentation examines neuronavigation workflows for precise, reproducible targeting with transcranial focused ultrasound (tFUS). Romain Duprat demonstrates the dedicated functions introduced in visor2 version 2.9: calibrating a transducer, creating its target, adjusting beam settings for the three-dimensional transducer representation, and performing target sonication. The session connects treatment planning and targeting with subsequent session review and data export, showing how the software supports the workflow from initial preparation through post-session analysis.

Chaoyi Zhang presents a method for observing distributed social-brain networks in awake marmosets during natural social interaction. Prefrontal, cingulate, striatal, thalamic and amygdala circuits are implicated in autism and other neuropsychiatric conditions, but have rarely been measured together during genuine primate social behavior. The platform replaces part of the skull with an acoustically transparent implant, enabling volumetric functional ultrasound measurements of cortical and subcortical activity at approximately 150-micrometre resolution. A whole-brain vascular reference and automated registration permit comparisons across roughly 50 atlas-defined regions, sessions and animals. Experiments show that a live social partner produces stronger and more extensive activity than video of the same partner. The talk considers applying this approach to genetically tractable, transgenic marmoset models of autism risk genes to identify altered network signatures and evaluate their potential as circuit-level biomarkers.

Intermediate-band solar cells seek to absorb photons below the host band gap and increase current without sacrificing voltage. This talk examines submonolayer CdTe quantum dots embedded in ZnCdSe matched to InP, avoiding a harmful wetting layer and permitting hundreds of absorbing layers. Recent growth results show deeper photoluminescence associated with larger dots and improved intermediate-band placement. A complementary inverse-design study optimizes ZnCdSe/ZnCdMgSe distributed Bragg reflectors to recycle photons over 1–1.8 micrometres and incidence angles of 0–70 degrees. Total absorption guides optimization, with designs showing broad reflectivity and tolerance to fabrication errors.

Runaway electrons can severely damage plasma-facing components in current and future tokamaks. This webinar presents a research roadmap connecting runaway-electron models with plasma–surface interactions and material-damage calculations. It examines the physics, experiments, model integration and validation needed to predict electron loads and damage at reactor walls. The speakers assess current capabilities, gaps in modeling chains, and challenges for ITER and subsequent fusion devices.

Simon Bates and Tom Concolino examine how analytical measurements can guide decisions in automated, closed-loop laboratories. They address limited or proprietary instrument interfaces, reliable connections between hardware and automation, and measurement and analysis workflows that deliver results at the speed an experimental loop needs. The presentation covers orchestration software, instrument integration, sample handling, and questions to resolve with instrument and automation vendors when designing a dependable self-driving laboratory.

Complementary nanoscale methods can extract different structural and material information from the same specimen, but combining them demands precise positioning and access. Alexandra Glück examines flexible multi-axis sample manipulation across electron microscopy, spectroscopy, diffraction, probing, nanoindentation and tomography. SmarAct’s customizable SEM platform illustrates approaches to alignment, measurement geometry and transitions between techniques, including in-situ experiments. The emphasis is on how adaptable manipulation enables complementary measurements to build a fuller account of a specimen’s structure and properties. An interactive discussion follows.

Gang Chen delivers MIT.nano's annual Dresselhaus Lecture, drawing on research that spans electron and phonon transport, thermoelectric energy conversion, microelectronic thermal management, desalination and data-center cooling.

Reference electrodes combined with electrochemical impedance spectroscopy can separate overpotentials and degradation processes at individual electrodes. Their placement in solid-electrolyte cells is constrained by geometry and pressurized gases, while noise and perturbations can make impedance measurements difficult to interpret. This webinar introduces reference-electrode arrangements and applications, then examines a proton-exchange-membrane water-electrolysis setup. Experimental results illustrate measurement artifacts and a proposed filtering method for recovering interpretable impedance signals. The presentation is followed by questions and discussion.

Claire Adjiman examines artificial intelligence across chemical discovery, product design, process design and process operation. The seminar explains how the appropriate use of AI changes with each activity’s objectives, available data and timescales. Examples across the product lifecycle illustrate potential benefits and unresolved challenges for chemical industries.

This seminar connects carbonization conditions with the structure and function of carbon made from discarded plastics and food-derived sugars. Commodity plastics are carbonized under autogenic pressure in sealed quartz capillaries; sugars undergo neutral and alkaline hydrothermal processing in water and ionic liquids. Time-resolved WAXS, SAXS and Raman measurements, supported by ex situ XPS, track organic networks as they become carbonaceous solids. SAXS identifies emerging porosity and density variation, WAXS follows short-range aromatic stacking, and Raman D and G bands measure evolving sp2 domains and defects. XPS distinguishes oxygen-rich hydrothermal chars from plastic-derived carbons with lower oxygen-to-carbon ratios and stronger graphitization signatures. The combined observations relate precursor chemistry to intramolecular rearrangement, intermolecular crosslinking, pore formation and aromatic ordering under pressure.