Instructables
2012-02-27 21.36.02.jpg
finger assembly.jpg
finger assembly1.jpg
This year for science fair, I did an engineering project with the goal of creating a system to provide haptic feedback from a robotic hand. The robotic hand is controlled by flex resistors on a glove worn on someone's hand, and an Arduino converts finger positions on the glove to finger positions on the robotic hand. Each of the fingertips of the robotic hand have their own force sensitive resistors(FSR) to gather information about pressure at each fingertip, and another Arduino converts the pressures to pulses for vibrator motors located on the fingers of the control gloves. I used two separate Arduinos since they only have 6 analog inputs each, and I needed 8. It also helped simplify the code a bit, since I used one Arduino for controlling the finger positions and the other for controlling the motor pulses. Also, I already had the two Arduinos, so I used them instead of buying an Arduino Mega or multiplexers. Anyway, the pressure readings are taken once every second, and the motors are on for a portion of each second depending on the pressure measurements. This means that the system is only accurate for a little bit each second, but the measurement intervals could easily be changed in the code. 

For the robotic hand, I sketched up a basic design in Autodesk and used the assembler feature to play around with and fine tune some of the finger measurements. Once I had my design ready, I took it to my local hackerspace and got all of the parts laser cut out of an acrylic sheet that was about 5mm in thickness. I bolted all of the finger parts together. As for attaching the fingers to the palm, I scratched the areas where the acrylic overlapped and glued the parts together. The glue worked fine, but if I build another hand, they will be bolted on. There were also a few issues with the placement of holes on the finger segments, but a bit of glue helped anchor the bolts down. To avoid this problem on later designs, I will use smaller bolts and try to cut out as much overlapping material as possible.

For wiring everything together, I found stripped CAT-5 cable rather convenient. It is a little stiff, but it comes out as pre-twisted pairs of wire. 

Also, there are only four fingers on the hand since there was only room for four servos on the palm area. To get a thumb in future designs, I will either move one of the robotic fingers to the side and move the sensors around on the glove, or just buy some smaller servos to make everything fit. 

In all, the project turned out well and provided a great starting point for future projects. I will eventually come back to this project, and when I do, I will definitely turn it into a step-by-step Instructable.

What CAD software do you use?

macgyver603 (author)  Chikpeas Brother7 months ago

I used Autodesk Inventor for this project. It had a nice simulation feature that allowed me to play with the design and see exactly how the fingers would move before I went about building them.

can you please tell me about the connections you have made

macgyver603 (author)  Nishant Das6 months ago

Check out my full instructable on this project for more information:

http://www.instructables.com/id/How-to-Build-a-Rob...

Neat! How much is it?

macgyver603 (author)  Chikpeas Brother7 months ago

Autodesk Inventor is one of the free downloads for students, so I was able to get my copy for free. I do not know how much it is otherwise.

http://www.autodesk.com/education/free-software

That's cool! Thank you for the info.

varora17 months ago
any chance ?? to get the circuit and block diagrams for wiring.. for this cool hand.. !!
makesomeso1 year ago
can u make a video of it in action
lean042 years ago
awesome, this could be used for remote surgery!!, it would provide sensibility to the surgeon.
Keep it up!
macgyver603 (author)  lean042 years ago
Thanks!
cShellPro2 years ago
This is a very interesting project.
Looking forward to your step-by-step
instructable. Well done!
mr fat2 years ago
Very very cool project! I look forward to seeing what else you build!
macgyver603 (author)  mr fat2 years ago
Thanks! I will be rebuilding the hand sometime soon, so I will be able to get pictures of the build process and make a step-by-step Instructable.
Thnak you! and yes I am working on something now;)