Toroidal counter electrode for ionic propulsion.

Significant attention has recently been given to applications of ionic wind to atmospheric propulsion. Rotational ionic engines (RIE) have also demonstrated to have potential for in-atmosphere propulsion in negative polarity. However, such devices have not yet produced enough thrust for a rotary ionic drone to be developed. We demonstrate here that a toroidal counter electrode can increase the RIE's performance by up to 7.8 times greater than in previous configurations (upper limit not determined). The RIE is designed with pin emitters extended on the trailing edge of a 12.6 cm two-blade plastic propeller placed above a toroidal counter-electrode which provided axial thrust up to 288.55 m Nat 23.15 N/m2, 4.2 m/s bulk airflow speed within the propeller plane, and 251 m3/h flow rate. The new design generates axial thrust due to the linear acceleration of ions between electrodes, and also due to the induced rotary motion of the propeller which captures the energy and momentum of ions accelerated in the propeller rotational plane. Thrust to power ratio can be measured by the ratio of voltage to current or propeller kinetic energy to power. A 4-RIE array matched the thrust (1 N) of a four-blade drone with similar blade size.

Controlled Synthesis and Characterization of Micrometric Single Crystalline Magnetite With Superparamagnetic Behavior and Cytocompatibility/Cytotoxicity Assessments.

A new class of magnetite (Fe3O4) particles, coined as "Single Crystalline Micrometric Iron Oxide Particles" (SCMIOPs), were obtained by hydrothermal synthesis. Both the single Fe3O4 phase content and the particle sizes range, from 1 µm to 30 µm, can be controlled by synthesis. The notable finding states that these particles exhibit vanishing remanent magnetization (σr=0.28 emu/g) and coercive force (Hc=1.5 Oe), which indicate a superparamagnetic-like behavior (unexpected at micrometric particles size), and remarkably high saturation magnetization (σs=95.5 emu/g), what ensures strong magnetic response, and the lack of agglomeration after the magnetic field removal. These qualities make such particles candidates for biomedical applications, to be used instead of magnetic nanoparticles which inevitably involve some drawbacks like aglommeration and insufficient magnetic response. In this sense, cytocompatibility/cytotoxicity tests were performed on human cells, and the results have clearly indicated that SCMIOPs are cytocompatible for healthy cell lines HaCaT (human keratinocytes) and HEMa (primary epidermal melanocytes) and cytotoxic for neoplastic cell lines A375 (human melanoma) and B164A5 (murine melanoma) in a dose-dependent manner.