Pressure-sensitivity technology for smartphones has been largely popularized by Apple and the iPhone 6S series but has yet to change the mobile world. Aside from the iPhone 6S and 6S Plus – both of which use 3D Touch – and the Huawei Mate S, there aren't a lot of smartphones utilizing force-sensitive displays. This may be due to the fact that this type of technology requires dedicated hardware, and in turn this can increase the manufacturing costs of a device. However, force-sensing technology could soon become widespread for any smartphone user, as engineers at the University of Michigan have created a software application that can add force sensitivity capabilities to any smartphone.
The software is called ForcePhone and is capable of turning any smartphone into a force-sensitive device. In fact, ForcePhone can turn not only a smartphone's display into a pressure-sensitive panel but the handset's entire body as well. Using the application, users can perform a variety of "force" gestures such as pressing harder on the surface of the screen or squeezing the smartphone's body, and in turn, each gesture triggers an event. But what makes ForcePhone unique is the fact that it bypasses hardware requirements. Apple's 3D Touch requires a special force-sensitive display and the technology relies almost entirely on hardware. In contrast, ForcePhone adds force-sensing capabilities to any device using ultrasounds – a technology inspired by the 2008 Batman movie "The Dark Knight". The application utilizes the smartphone's speakers to produce an inaudible tone at a frequency higher than 18 kHz and then uses the handset's microphone to pick up the vibration caused by the speakers. The tone naturally changes whenever a user applies force to the smartphone's display or body, and once the microphone detects those changes, it translates them into commands.
Yu-Chin Tung, a doctoral student and one of the developers of ForcePhone, is of the opinion that current force-sensitive solutions increase production costs, which is why not many smartphone makers have been eager to hop on the bandwagon. However, Yu-Chin Tung also believes that their "sound-based solution can fill this gap, providing the functionality without making any hardware modification". ForcePhone will be presented in Singapore at MobiSys 2016 between June 27-29 but details regarding a commercial release are missing.