What materials are pacemakers made out of?

Several things: The case is made of titanium, the batteries are lithium, /iodine cells, the electrodes are thin insulated wires, and the circuit boards contain resistors, diodes, capacitors, and semiconductors. The circuit boards function like a small EKG machine sensing spontaneous heart beats and if the heart does not beat, they send a small shock down the wires to make it beat.

Biocompatable stuff: There are multiple components, but all must be nontoxic, not cause immune sytem to react, sterilizable, and able to work in wet, warm and mobile environment. Usually the case for the pacemaker is made of titanium or a titanium alloy. The lead is also made of a metal alloy, covered with polyurethane or silicone. Other components are sealed inside the case and are not exposed to react to the body.