  Selective hysteretic heating of multiple collocated sets of single domain
magnetic nanoparticles (SDMNPs) by alternating magnetic fields (AMFs) may offer
a useful tool for biomedical applications. The possibility of magnetothermal
multiplexing has not yet been realized, in part due to prevalent use of linear
response theory to model SDMNP heating in AMFs. Predictive successes of dynamic
hysteresis (DH), a more generalized model for heat dissipation by SDMNPs, are
observed experimentally with detailed calorimetry measurements performed at
varied AMF amplitudes and frequencies. The DH model suggests that specific
driving conditions play an underappreciated role in determining optimal
material selection strategies for high heat dissipation. Motivated by this
observation, magnetothermal multiplexing is theoretically predicted and
empirically demonstrated for the first time by selecting SDMNPs with properties
that suggest optimal hysteretic heat dissipation at dissimilar AMF driving
conditions. This form of multiplexing could effectively create multiple
channels for minimally invasive biological signaling applications.
