The interesting thing about this project is that they're using transistors to physically simulate synapses and neurons, which is quite an inefficient method. Transistors are expensive, and your brain has about 100 billion neurons, and trillions of synapses.
A recent discovery by Leon Chua has shown that synapses and neurons can be directly replicated using Memristors [1]. Memristors are passive devices which may be much simpler to build in the scale of neurons compared to transistors.