A different type of material? Like what? Do you really think we can "bake" up a chemical compound that functions like a neuron and put it in a 3D printer? It's not that easy.
It's not difficult at all to do this. However, modeling a single neuron is not the level of modeling that you want to focus on. You want to focus on the mesoscopic level of the population that we model as coupled oscillators. You can model on the order of 10,000 neurons as a "node" and use one parameter as a "weight" to simulate the modifiable synapse. We can simulate these using non-linear coupled ODE's. Again, it's not that difficult to simulate these oscillators in electronic circuits.
http://sulcus.berkeley.edu/wjf/DF_Principe_IEEEAnalogVLSI.pdf
We've found that the limiting factor is in the complexity of the scaling factor of the oscillators. The actual biological brain is a 3D structure which allows for a rich and complex interconnectivity. Trying to emulate that 3D architecture with electronic circuitry is the current challenge we face.