Self-healing first-wall coatings with embedded radiation diagnostics
Provost's Postdoctoral Fellowship, Mutlu group
The first wall of a fusion reactor is the innermost barrier between the plasma and the machine. It degrades under intense radiation and has to be inspected and replaced on a schedule, and silicon sensors cannot survive close enough to watch it happen. Monitoring today is therefore indirect during operation and physical after shutdown.
This project pairs two things that are usually developed separately. The coating side uses combinatorial thin-film growth to search high-entropy alloy compositions that tolerate radiation damage and recover part of it, covering a composition gradient in a single deposition run rather than one sample at a time. The diagnostic side embeds graphene nanoribbon devices in the same stack. Together the target is a wall that resists damage and reports its own condition while the machine is running, which changes the maintenance model for a power plant.
Graphene nanoribbon radiation sensors
Provost's Postdoctoral Fellowship, Mutlu group
Ribbons synthesized to be exactly nine atoms wide keep their atomic framework under gamma exposure while their transport changes sharply, because at that width small chemical changes at the ribbon edges localize the charge carriers and cut the current. Surviving the dose while responding to it is exactly what a sensor needs.
My part is synthesis and devices: growing atomically precise ribbons by molecular beam epitaxy, integrating them into transistor structures, and mapping how the response scales with dose and with ribbon geometry. The same approach applies to spacecraft, where state-of-health data on communications satellites, Earth-observation satellites and deep-space probes would catch radiation wear before it causes failures.
Armchair graphene nanoribbon transistors for logic
The same nine-atom-wide ribbons are among the strongest candidates for taking chip technology past the scaling limits of silicon, because a ribbon that narrow has a real bandgap where a graphene sheet has none. The open questions are practical: contact resistance, gate control at this width, alignment and yield across a wafer, and whether the on-off ratio holds at a current useful for logic.