How to Build an Artificial Synapse

Artificial synapses can be built with basic electronic components on breadboards. The artificial synapses are made with an optocoupler, diode, and a resistor. Transistors are used to buffer the input and output signals.

The transmitting side of the optocoupler can be built with an LED or an IR LED. The receiving side of the optocoupler can be built with LED, photodiode, phototransistor, or light-dependent resistor LDR.

Excitatory synapses send charge into the capacitor of the postsynaptic neuron. For an inhibitory synapse, a transistor is used as a switch which allows current to flow from the capacitor to the ground reducing the amount of charge in the postsynaptic neuron.

An animation of how a biological synapse works is also shown. How a biological synapse functions is compared to how the artificial synapse works. The key is to have the artificial synapse be functionally equivalent to the biological synapse. A proportional amount of charge or number of states needs to be transferred for the the synapse to be properly replicated.