A Northwestern Neuroscience and Robotics (NxR) project to manufacture and distribute phones with variable friction capabilities to the haptics and human-computer interaction community in Fall 2017.
Over the summer of 2017 I built and tested mobile phones with variable friction capabilities. These mobile devices can simulate the feel of a texture, shape, or dynamic force on your fingertip on a flat, glass screen outfitted with a piezo and controlled by an auxiliary PCB. I collaborated with a PhD student who was developing an application for the phone, while I prepared 35 phones for shipment to other labs and engineers.
The community is open-source and collaborative, allowing NxR to receive data through applications pushed out to the phones, while giving other scientists the ability to exploit the technology for their own research.
A few steps in the process included documenting the assembly, brainstorming with the surface haptics group regarding a new method of reverse engineering textures using SynTouch Inc's 15 dimensions of texture, and setting up the calibration process with a laser dopper velocimeter (LDV) to find an optimal operating frequency for each phone.
The 35-phone build was completed at the end of August, with units ready to distribute to other research groups. Throughout this project I gained contextual knowledge about surface haptics applications, signal processing theories, and variable friction devices, which was necessary to understand the dynamic system I was building and testing.
Specific skills I used included 3D printing to set up a calibration station, laser cutting and modifying g-code for the piezo gluing process, and modifying an Android app for the device to sweep through various frequencies during testing.