Blast induced electromagnetic pulses in the brain from bone piezolectricity

The mechanisms that might lead to in-brain electromagnetic pulses from an IED-scale explosive are considered, along with whether the resulting fields might have timescales and magnitudes relevant to neurological processes. In particular, due to known piezeoelectric properties of bone, it is possible for a shock wave incident on the skull to directly induce large electric fields within the brain. Using experimental data on the piezoelectric properties of bone combined with stresses from full-head-model blast simulations, the resulting in-brain electric fields shown to have timescales and magnitudes that exceed IEEE safety standards are comparable to procedures such as transcranial magnetic stimulation that are known to have neurological effects. Not only are such electromagnetic fields at least potentially relevant to the understanding of blast-induced traumatic brain injury but they may also lead to diagnostic tools in the form of blast dosimeters that measure blast-induced head stresses via the piezoelectric fields produced just outside the skull. [This work was supported by financial aid from the Joint Improvised Explosive Device Defeat Organization (JIEDDO) through the Army Research Office.]