Requirements for a successful implementation
There are three elements to a successful fingerprint sensing implementation. The mechanical design of the sensing pad, the sensitivity of the controller IC, and the algorithms running on the IC for accepting or rejecting fingerprints.
The sensing controller IC and the software it runs may be sourced from third-party suppliers such as Synaptics. Synaptics has the advantage that its automotive fingerprint sensor solutions draw on technology shipped in tens of millions of smartphones worldwide. The learning and development baked into this technology ensure that automotive implementations can achieve just as high a performance as implementations in the mobile phone.
The mechanical design – the area and thickness of the sensing pad, the material it is made of, and its positioning in the vehicle – will be decided by the car manufacturer. Here, OEMs may draw on the experience that Synaptics has had in the smartphone market: smartphone manufacturers have experimented with many different configurations of the sensing pad, for instance. Some have worked, some have not: knowledge of previous design iterations will allow automotive manufacturers to complete sensor designs faster and avoid experimenting with design configurations that are known not to work.
As a proven technology, then, the capacitive method is set to be the first technology for fingerprint sensing to be adopted in the car. Time will tell whether it turns out to be preferred by the automotive industry in the longer term, and no doubt optical, ultrasonic and other technologies will be evaluated, and other forms of biometric sensing