Like every other investment such as real estate, stocks and other forms of investment we know that you can invest in that kind of things and then you get something like say a Certificate or a Binding Document as a proof that you are part of that investment, now that of bitcoin all you have is just your address, your password, key and seeds as proof of the ownership of the wallet.
BTCSo now if one is considering buying bitcoins and saving for his/her children in the future is there any way to do that with bitcoins apart from having to write down your details somewhere. I'm asking because with that kind of stuff if no one knows your seeds or password no one can get the coins.

Saving your bitcoin for your children is a good idea but you need to undertake the possibilities that if no one could'nt know your passwords you have to make a wise decition that when you are able to pass your bitcoin to your childrens. You must look to your children who is able to handle and trustworthy so you can gave to him/her your bitcoin. Since you cannot assure on when time you are going to die,so the best idea is you have to assure it than leaving it .