Meet the Mark VII Mindstorms Robotic Hand and Arm: a wearable creation with 4 motorized fingers controlled individually by four touch sensors and powered by one Mindstorms EV3. It was displayed at LEGOPalooza 2015 in Chapel Hill, NC. As you can see in the below video, the Mark VII allows the wrist to stay flexible:
The hand is not connected to the arm. It took the developer 6 hours to complete the project. Unfortunately, there are no detailed instructions on how to make this particular robotic hand and arm. But you can always follow Diavo Voltaggio‘s work to find out about his future projects, which will surely be very exciting.