Materials Bound by Non-Chemical Forces: External Fields and the Quantum Vacuum
We discuss materials which owe their stability to external elds. These include: 1)external electric or magnetic elds, and 2) quantum vacuum uctuations in these elds inducedby suitable boundary conditions (the Casimir e ect). Instances of the rst case include theoating water bridge and ferrouids in magnetic elds. An example of the second case is takenfrom biology where the Casimir e ect provides an explanation of the formation of stackedaggregations or \rouleaux" by negatively charged red blood cells. We show how the interplaybetween electrical and Casimir forces can be used to drive self-assembly of nano-structuredmaterials, and could be generalized both as a probe of Casimir forces and as a means ofmanufacturing nanoscale structures. Interestingly, all the cases discussed involve the generationof the somewhat exotic negative pressures. We note that very little is known about the phasediagrams of most materials in the presence of external elds other than those represented bythe macroscopic scalar quantities of pressure and temperature. Many new and unusual statesof matter may yet be undiscovered.
Evangelos Hristoforou and D.S. Vlachos
J. Swain et al., "Materials Bound by Non-Chemical Forces: External Fields and the Quantum Vacuum", Key Engineering Materials, Vol. 543, pp. 314-317, 2013