Piezoenergetics Coupled Piezoelectric and Nanoenergetic Materials with Tailorable and Switchable Reactivity

2018 AFOSR MURI
Piezoenergetics Coupled Piezoelectric and Nanoenergetic Materials with Tailorable and Switchable Reactivity
PO: Dr. Mitat Birkan
PI: Dr. Steven Son, Purdue University
co-PIs at Penn State, Case Western University, University of Maryland, and Georgia Tech
MURI Website

     Piezoelectric energetics (piezoenergetics or PEs) offer the potential for a new generation of smart propellants and pyrotechnics with multifunctional capabilities that can be actively controlled via external stimuli. However, the fundamental physics and chemistry governing the energy transfer, energy repartitioning, and chemical reactions/kinetics resulting from external stimulation of PEs are not well understood. It is envisioned that by coupling piezoelectric behavior and nanoenergetics truly smart and switchable materials can result. The full range of possible PEs is ripe for exploration; however, fundamental multidisciplinary studies are needed to realize controlled and adaptable energetic materials that result in disruptive (orders of magnitude) changes of reaction rates, ignition, and switchable (on/off) responses, while simultaneously serving as in situ sensors.

     This multidisciplinary team has unique expertise and resources for this topic. Our approach includes (i) simulations (at both atomistic and continuum levels – Zhou and van Duin), (ii) advanced experimental diagnostics (Son, Yetter, and Zachariah) for selective interrogation of materials and reaction rates over a wide range of time scales (from ignition/combustion to detonation), and (iii) novel synthesis (Sehirlioglu and Wang) and fabrication methods (Son, Yetter, and Zachariah) to produce model systems with specifically targeted properties. This is an integrated materials study, design and development effort: simulations will guide and inform materials design, synthesis, fabrication, and experiments; and experiments and atomistic calculations will provide necessary constitutive and property parameters (piezoelectric, thermal, dielectric and chemical) for micro- and macroscale continuum modeling.

     The focus of this effort will be twofold: develop a fundamental understanding of mechanistic processes required for energy transfer with a tightly-coupled synergistic experiment-simulation approach, and synthesize/fabricate novel materials informed by multiscale simulations that exploit piezoelectric control mechanisms towards unique behavior propellants and reactive materials with in situ sensors that monitor health or performance. Our approach is designed to achieve these objectives to answer questions such as (i) What range of PEs are possible and which are best suited for propellants or reactive material applications? (ii) What are the important physics and chemistry of PEs, and how can piezoelectric effects affect reaction? (iii) How do multiscale control of structure and morphology, as well as interfacial structure, affect both ferroelectric and reactive properties? (iv) What are the critical interactions between charge, mechanics, and reaction response? (v) How do these systems respond to external stimuli? and (vi) How can the above effects be manipulated to tailor, adapt, and control the performance of PEs

     This work will provide the basic research (theory/simulation, synthesis, fabrication, and characterization) needed to answer these questions and to enable the a priori design of multifunctional PEs that are tailorable, adaptable, and switchable. To ensure we achieve the objectives, this MURI project emphasizes 1) design and experimentation guided by multiscale/multiphysics simulations (atomistic, micro/macro continuum, coupled mechanicalthermal-electrical-chemical), 2) synthesis/characterization of novel PEs based on piezoelectric oxides/ceramics and polymers (both also serving as oxidizers), and 3) Fabrication/integration of the constituents into reactive materials and propellants with detailed characterization of their attributes and interfacial interactions with novel experiments.