Friction braking will of course continue to dominate, and it will be years before automotive brake pads actually become redundant. Because of the changed braking behaviour, though, cars will brake less frequently and that will impact the material properties of both pad and rotor.
First, pads are likely to change in shape. The brake surface area should increase because larger batteries mean heavier cars. And the pads should become thinner to reduce weight, which is possible since there’s less wear.
Noise is becoming more important, which is a challenge for brake pad and rotor manufacturers. This is more of an issue with electric vehicle braking because even relatively quiet brake noises are audible from EVs since they are almost silent.
Corrosion on rotor and pad will become more important too. With ICE vehicles, regular brake use cleans any corrosion. With EV drivers using friction brakes less often and with less brake pressure, rust can build up on the rotor and brake pad surface. This can seriously impact the braking performance and create a safety issue. Applying the friction brakes several times can clean rotor and pad surfaces.
Braking will focus less on brake pedal ‘feel’ because an increasing number of cars will integrate electronically controlled brake boosters in which pedal feel is managed by software rather than the pad’s direct response.
We are also seeing something of a return to drum brakes on the rear axles of cars.