Nanohelix is considered a new and attractive building block element for designing a set of new synthetic nano-actuators and -sensors and combination of them, namely nanorobotics which has broader applications; biomedicine, nanomedicine, key catalyst for synthesis of pharmaceutical medicine, key electrodes for energy devices (battery, solar cells, etc), and proximity tactile sensor of soft-matter robotic hands. If the nanohelix is mechanically flexible and made of magnetically active material, which is controlled under applied magnetic field, such magnetically active nanohelix can be designed into a new robotics system for diagnosis and treatment of difficult-to-treat cancers. The proposed nanorobotics can have multi-functions; (i) swimming under magnetic guidance, thanks to the shape of "helical spring", (ii) mechanical vibrations of the nanorobotics with flexible nanohelix under applied magnetic field and gradient, thus, killing cancer cells due to mechanical stress loading, and (iii) magnetically active material for nanorobotics plays also as a magnetic resonance imaging enhancer, thus, accurate locations of the nanorobots if they are attached to cancer cell sites, can be identified by the magnetic resonance imaging.
We recently synthesized iron-palladium alloy nanohelices by using chemistry processing route; alumina-silica template and electroplating to make solid-state iron-palladium alloy nanohelices. This iron-palladium alloy nanohelix is down-sizing from our previous design of macro-iron-palladium alloy spring which exhibited the fast vibrations under applied magnetic gradient. The key scientific mechanism associated with the macro-iron-palladium alloy spring, which we discovered is a new actuation mechanism (hybrid mechanism), a set of chain-reactions; applied magnetic gradient, magnetic force, stress induced martensite phase from austensite phase, resulting in fast-actuation within a very short time. We recently made molecular dynamics modelling to simulate another actuator mechanism of iron-palladium alloy nanohelices under applied "constant" magnetic field. We also synthesized another nanorobot which is composed of iron-palladium alloy cylindrical head (head) and nanohelix where we can replace the iron-palladium alloy head by an iron head, thus, the nanorobot based on the combination of iron head and iron-palladium alloy helix may serve more effective nanorobot concept. The goals of the proposed NSF project are multi-fold: (1) to prove the hypothesis driven mechanical stress-induced apoptosis of cancer cells by using the nanorobots under magnetic field, (2) to establish the optimum navigation control of the magnetic nanorobots and (3) to demonstrate the effectiveness of the nanorobots for cancer diagnosis and treatment using in vitro experiment. To achieve the above goals, we propose the following five tasks over a three-year period:
Task-A: High-yield processing of magnetic nanohelices and their nanorobots (Taya) Task-B: Characterization of the nanostructure and properties of iron-palladium alloy nanohelices (Taya) Task-C: Modeling work (Kuga/Taya) Task-D: Production of nanorobots containing solution for apoptosis study (Takao/Taya) Task-E: In vitro experiment for magnetic nanorobots under applied magnetic field/gradient (Lee/Kuga)
The broader impact of this proposal is that the proposed nanorobots based on magnetic nanohelices, leading to opening up new applications discussed above. We plan to incorporate the results into education,i.e., into the existing graduate course on active and sensing materials and their integrated systems and educational summer program at University of Washington. The intellectual significances of this NSF project are: (i) to establish high-yield processing route for key building block element of nanorobots, i.e. iron-palladium nanohelices, and combined magnetic head and iron-palladium alloy nanohelix , (ii) to study if the hybrid mechanism of actuation in magnetic nanohelix is realized, (iii) to construct a cohesive model for an accurate control of nanorobots navigation, (iv) to test the hypothesis of mechanical stress loading-induced cell death and (v) to design Helmholtz coil system tailored for accurate navigation of nanorobots.
