Google will have a working prototype of its “Project Ara” modular smartphone concept ready “this month”, MIT Technology Review said.

The publication said that more than 100 people at “a dozen companies” are involved in the project, which is being led by Motorola’s Advanced Technology and Products (ATAP) group. This unit is being kept by Google when the sale of the bulk of Motorola Mobility to Lenovo goes ahead.

The idea behind Project Ara is not new: to create a smartphone that can be modified by the addition or substitution of modules – Motorola previously suggested that this could be “anything, from a new application processor to a new display or keyboard, an extra battery, a pulse oximeter – or something not yet thought of”.

Paul Eremenko, who heads ATAP, said: “We believe that the smartphone hardware ecosystem should be, and can be, a lot more like the Android app ecosystem: with a low barrier to entry, lots and lots of developers, and faster, richer innovation.”

MIT Technology Review noted that modular designs have traditionally come with design penalties that make them less appealing to consumers, for example in terms of size and weight.

“Modular things tend to be brick-like. We think we’re at an inflection point where the penalty is down to something that can comport with things that would be beautiful,” Eremenko said.

And the report also notes that while in developed markets customers are familiar with fully integrated smartphones, there are opportunities in other markets.

Google hopes to test a $50 device with “a Wi-Fi module, basic processor and memory, battery and screen” in “a South or Central American market where cellular minutes are expensive but Wi-Fi hotspots are common”.

Several earlier modular smartphone efforts failed to gain traction in the market, for example with the Qualcomm-backed Modu closing its doors in 2011.

This was followed by Google acquiring intellectual property from Modu.