hmm.. i've done loads of investigation in chemistry - making aspirin, extracting copper, making plastic that conduct electricity, titration.. most of the things i've done it.. im not sure whether you do it in phils coz we use a lot of different chemicals, some of which is in their concentrated solutions. parang industrial chemistry na kc ginagawa nmin eh.. although 1st year college lang yun..
biology.. hmm.. my friends have done chocolates with hard outlayer but soft inside..
physics? hmm... in my former school in philippines they made a blackboard eraser... i forgot what's unique about it pero may pinanalunan nman sila... you can actually make a dynamo (electromagnetisim) that could operate a small gadget... e.g mag-bbike ka for how many hours para charge yung phone mo... something to do with generating electricity...