Dielectrophoresis(DEP) and travelling wave dielectrophoresis(TWDEP) based cell manipulation using microfluidics

Microfluidics is a new trend in medical instrumentation to miniaturize the size of medical devices used in laboratories. Bacterial cell manipulation can be done using “Travelling wave dielectrophoresis(TwDEP)” technique on a Lab on Chip device. In traditional DEP method, polarized cells get either attracted or repelled from electrodes depending on their dielectric properties and size, hence, get separated vertically. In order to collect these separated cells at the outlet hydraulic drag force is required. Whereas in the case of TwDEP cells get vertically separated like normal DEP method and along with it they also get pumped at output, horizontally due to travelling wave. This travelling wave is generated by applying voltage with phase difference at each electrode. Such voltage creates non-uniform electric field with phase shift and hence has force on cells on both the axes. Such devices can be connected to external electric circuits and can be used as bio-sensors

Thermo-magnetic shape control of nano-ferromagnetic particle doped shape memory alloy for orthopedic devices and rehabilitation techniques

Recent advancement in smart materials facilitated the use of Shape Memory Alloy(SMA) in treatment of different orthopedic problems and rehabilitation technique to treat paralyzed patients. But Shape Memory alloy lacks the controllability while regaining the shape from martensite to austenite during thermal loading. Therefore, in this paper we introduced a mechatronic device which provides the control over the shape change of new hybrid material having property of SMA and shape memory property of anticipated material is verified by finite element analysis in COMSOL Multiphysics. In the proposed methodology the shape is controlled by generating a controlled thermo-magnetic loading, and hybrid material formed by doping a nano-ferromagnetic particle in porous NiTi SMA. For the proof of the concept an experiment is carried out by using a bimetallic strip, microcontroller, sensor and proper feedback circuitry system and it is observed that for the supply of 4V and bent angle for flex sensor between 0 to 40 degree, current through the solenoid is 3.63A producing Magnetic field of 1.42mT and for flex sensor b ent angle 4 0 to 7 5 degree the current through the solenoid is 1.2A producing Magnetic field of 0.47mT for same supply and if the flex sensor bent angle increases more than 75 degree then the voltage supply cutoffs which indicate the absence of Magnetic field