A number of techniques will be used to prepare these engineered nanoparticiles. Notable among them are a Microemulsion technique (b) Coacervation technique etc. Recently, at IITB we have prepared core and shell nanoparticles by using some mixing protocols of reactive water-in-oil microemulsions. This technique, known as post core technique, uses the general type of reactions, A+B?D, and C+B?E to produce core of D with shell of E wrapped around it. In the post core technique, a water-in-oil microemulsion containing reactant A is mixed with another water-in-oil microemulsion containing excess of reactant B. The resultant microemulsion will have nanoparticles of D and excess of B molecules. To this, a third microemulsion containing reactant C is added to produce core (D) and shell (E) nanoparticles. Choosing the reactants, A, B and C, a number of different types of core and shell nanoparticles can be prepared. It has also been found that instead of post core addition, if all the three microemulsions are added together, then one obtains nanoparticles of D and E composites. Choosing the reactants, A, B, and C and their compositions we can prepare a variety of composite nanoparticles. Both core and shell and nanocomposite nanoparticles preparation using microemulsion and other techniques need further work to develop a technology. Proper characterization of these nanoparticles also has remained as a very challenging task. Studies will be conducted to develop the methods and procedures to prepare engineered nanoparticles with desired characteristics on morphology as well as with functional applications in health care, chemical technology, electronics, materials sciences, and so on. A simple engineered nanoparticles will be that of core and shell of completely coated shell. A complex one will be to prepare core and shell of uniform coat and have a particular shell thickness. An even more complex one will be to produce shell of some desired characteristics, which may involve choosing a specific material, E. Or, it may involve a composite shell. A very challengingly complex engineered nanoparticle will be nanoparticles that have more than one layer of shell and each shell having some desired characteristics and functionality. The work will be both experimental and modeling in nature.