Connectors between the main base unit and the other modules are also a big performance challenge. If we see integrated designs, these are set up for high performance. Connectivity between different units is highly optimised, but breaking this up and building external connectors that operate at similar performance levels would be a huge challenge.
Any external connector connecting different modules would give the device a ‘Lego’ kind of look, while at the same time making it bulkier. Moreover, such a modular system would consume more power, since hot swappable and standard connectors would now replace the more fine-tuned custom connections.
Will connectors be the knell of doom?
Well we have alternatives; the device doesn’t have to be connector based in the first place. Today, we have architectures which do not require any connectors, by having their electrical interfaces defined in the mechanicals of the device itself. This way the PCB of any module can be connected with the PCB of the other modules without the standard connectors. Or the casings of modules could have embedded electrical interconnects to connect the modules.
Nate Srinath, founder-director, Inxee, explains, “If we look at the phones today, we are moving towards thinner and thinner architectures, so most connectors available are big for these. We have to look for very fine customised, thin connectors which are very durable and can make multiple modules connect. Some architecture doesn’t have any connectors but the electrical interfaces are defined in the mechanicals itself. If we can dream, there are so many ways to do it, but the bottom line is somebody has to standardise it and then make everybody adhere to it.”
Let’s talk solutions
A plausible solution could be electro-permanent magnets. Electro-permanent magnets are passive in both on and off states and can be used to transfer data as well as power. These require a voltage for transition between two states and their off-state magnitude is lower. But when turned on, their magnitude increases many folds, which is good enough to hold different modules. Also, eliminating any external connector, these connections would allow the device to be slim and maintain its aesthetic looks.
Another contact-less power and communication interface technology which might help is capacitive media converter. The technology is still in development phase where coupling occurs by capacitance at higher frequencies and inductance at lower frequencies. Experts believe that if connectors are avoided, it could also help in reducing the additional industrial design overheads related to increased volume and weight.
But one needs to carefully consider contact and contact-less options while going for the connections between modules. Ashwin Ramachandra, VP and head, ErND Practice, Sasken Communication Technologies, explains, “The moment you look at contact-less options, a new problem immediately comes up. Integrating issues with respect to signal, power and bandwidth will definitely be there. But for the areas like when you are connecting the processor with memory you can’t afford to overlook these issues, you need a fairly strong connector or a critical line connecting processor to the memory.”
Swapping those modules
A modular phone presents the idea of swapping different modules and configuring the phone features by ourselves. But how can we really swap a camera module with a battery module, or a memory module with a Wi-Fi module?