In-Operando Rejuvenation of Materials and Devices

What do a machine structure, a gas turbine blade, a sensor, a rechargeable battery, a transistor, and a neutron moderator (among many other things) have in common?

They all degrade—sooner or later.  The harsher the operating conditions, the faster the degradation. The unified challenge across diverse materials and components is to withstand harsh environment (high temperature, stress, radiation, corrosion). Existing approaches include developing new materials, designing better systems, performing maintenance, or building in redundancy.

We are pioneering a new philosophy called rejuvenation. What if we could mitigate all the defects and damage in these components so they behave like pristine versions—or even better? Imagine a rejuvenation process that takes just a few seconds and is non-intrusive, unlike preventive maintenance, which often requires disassembling the faulty item. With this approach, we could periodically rejuvenate components in-operando, enabling them to last longer even in harsher conditions. This is not achievable with traditional thermal annealing, as it requires high temperatures, long durations, and a controlled furnace environment, making it incompatible with in-situ operations.

Bridging the gap between material science and practical engineering solutions: Our work focuses on rejuvenating transistors and diodes, battery anodes and cathodes, nuclear cladding, other thin-walled structures, and even nuclear graphite. Our process operates at room temperature (we have annealed Tungsten and Graphite below 30 ºC), though the presence of low to moderate heat can enhance its effectiveness.

Chasing defects: Rejuvenation is just the outcome. At its core, our research delves into defect nucleation and evolution across a wide variety of materials subjected to mechanical, thermal, electrical, radiation, and electrochemical stresses.

 

Current Focus

  • Room temperature rejuvenation of radiation degraded electronics. Keywords: diodes/transistors; proton/heavy ion/gamma/neutron; silicon/silicon carbide/gallium nitride/gallium oxide.
  • Failure physics of electronics in harsh environments. Keywords: diodes/transistors; high temperature/biasing/stress concentration; high resolution microscopy/spectroscopy
  • Ultrafast rejuvenation/recrystallization of metals and alloys. Keywords: high temperature alloys; harsh environment sensors; battery anodes/cathodes
  • Multi-scale defects in nuclear graphite and impacts on fracture and creep. Keywords: x-ray computed tomography;  high resolution microscopy/spectroscopy

 

Analytical Tools

We design and fabricate our own setups to run in-situ experiments inside the transmission electron microscope. From biasing diodes/transistor to mechanical probing, or simply heating up the specimens – the TEM is our favorite tool. Shown left is our MEMS chip with heaters, electrodes, actuators and sensors. The small footprint makes it compatible with virtually all forms of microscopy. We also use electron backscattered diffraction, x-ray diffraction, x-ray computed tomography and Raman spectroscopy.

Our unique approach combines mechanical, thermal, and electrical measurements with microscopy, enabling us to “see while we measure.”