Introduction: How to Make a Human Camera - the Making of Touchy

By Eric Siu
About: Eric Siu is a Hong Kong new media artist who has a broad interest in animation, video, installation, kinetics and interactive art. He is currently a resident artist of the Ishikawa Oku Laboratory at the Univer…
My name is Eric Siu, a media artist from Hong Kong and the creator of Touchy, which is a collaborative project with Tomohiko Hayakawa and Carson Reynolds. Touchy is a social interaction experiment that focuses on the relationship of giving and receiving by literally transforming a human into a camera. The person wearing Touchy is blind until you touch their skin, then the eyepiece opens and they can take photos for you. This human camera, with its unique properties, aims at healing social anxiety by creating joyful interactions.

For this project I transposed the functions of a digital camera to a wearable helmet comprising of a pair of automated shutters, a functioning camera and an interactive screen. The shutters are used to blind the wearer of Touchy, only your touch will activate their opening and allow Touchy to see. When a human contact is maintained for 10 seconds, the front facing camera captures an image, which is displayed on the back facing screen for the user to access.

Metaphorically, Touchy lives in an isolating cage built by the experience of total darkness, as if they are encountering the same sensuous withdrawal as some social disorder patients. An effortless touch by someone else is an action of giving vision and taking photos, which heals the anxiety and generates a playful interaction that invites people to have fun and reinterpret the way we think about and use cameras.

Some obstacles are solvable by accessible technology and moderate electronics knowledge, others require more expensive solutions or intensive technical research (such as the sensor), which is still a work in progress with the sensor research team. Moreover, in this instructable, I will also include comments from Tosa Novmichi@Maywa Denki, my project adviser, who has been valuable in Touchy.

This Instructable is divided to following parts:
  1. Design
  2. Prototype
  3. 3D modeling (Solidworks)
  4. Mechanical and Electronics design
  5. The Touchswitch Sensor Research and Experiment.
For further reading into Touchy please check out touchtouchy.com

Step 1: Design

At the beginning of the design phase it's important to produce a lot of sketches, conduct studies, and research your design choices. Compare the advantages of each in terms of aesthetic and practical means.

The first sketch of Touchy illustrated something way simpler (as a pair of goggles) than the finished product and of course that was overly optimistic because there is no way for me to embed all electronics in this design. After further brainstorming I decided a key point that guides my design - the device should be able to make direct association to a camera object. Like when people see it they should say "Look, it's a camera! On someone’s head?!" The sketches extend to this direction and in the third image I try to reference Polaroid cameras because they are fun and toylish. However, this idea is still not very realistic and it doesn't direct our association to camera precisely.

Next I thought to convert the entire head to a camera instead of just the eye. In this sense, the eyes would be the lenses of the camera and the head/brain of the person is the body/brain of the camera. I compared the camera helmet idea to the camera goggles and created different evolution of possible design.

Note:
As an artist who has never really worked as a product designer working on this product-like project, there was one question came into my mind - should I design the object from outside in? Or inside out? This was a very critical question. When I started from the outside, I always worry if it will fit everything inside, on the contrary, if I start from inside, I am afraid some decisions might make the outside ugly. It's a very difficult balancing game especially we couldn't confirm how much electronics components we have to embed into the helmet. I asked this question to Tosa, and he said he used to do outside in, so that you won't lose your desired shape and design. What happen inside is always more flexible and solvable. I agree with that and I also find it important to work within limitations that you have to pin point some elements in your project that almost unchangeable and work around it. Like Apple might have their first iPad 1 as thin as the iPad 2 if the screen and battery could be thinner (of course, despite their business strategy.)

I finally chose the design of the last image, and it still somewhat an intermediate, but it is good enough for prototyping.

Step 2: Prototype

After choosing the design, I drew four views (front, top, side and back) of the helmet for the prototyping process. Thanks Tosa for letting me to use his studio for this purpose since I don't have one in Japan.

Before jump into 3D modeling it's always good to build simple prototypes with easy to use materials, such as foam board, cardboard, paper, modeling plywood, etc. Modeling your design in software takes a lot of time, and a simple prototype model can quickly give you an idea of how your design look like in real 3D. Particularly for this wearable device project, without a prototype, I would have no idea how to define the dimensions of the object.

I created my prototype by measuring my head, getting the approximate dimensions of the enclosure of the helmet and the shutters location from the distance of my eyes. I also knew that there was going to be a space limitation from the motors I used , they are located quite close to the eyes so I have to make sure it won't hurt myself when designing the prototype. From the first version of prototype I found the camera hood blocks too much of the eyes, so I decide to take away this cool feature to simulate a camera with normal lens.

Prototyping further the design was getting closer to what I wanted, but still felt bulky. Once approach to reducing the bulk was to make the top curve inward and reduce volume. I simulated this by layering several foam boards on top each other and sanding down the edges.

Prototyping can be a very long process (James Dyson made 5,127 prototypes before the first model DC01 launched). After I was satisfied with the rough prototype I took the design into Solidworks for 3D modeling, referencing my physical prototype for scale and dimensions.

Step 3: 3D Modeling (Solidworks)

Solidworks is a great 3D CAD software mainly for engineering and product designers. This is not a step-by-step Solidworks tutorial, but I will share the key phases of the development of the project.
  1. The first task I wanted to process was the mechanical design of the shutters, I was most worried about this part as I am not an Engineer. As a newbie of Solidworks it was a good task for me to practice the software. The shutter is an off-the-shelf product, which is simple enough to hack. I measured all the dimensions of the shutter and modeled it for gear design.
  2. After I have the dimensions and the model of the shutter, I search for approximate gear from sdp-si and modify their model to fit my designed gear, which has to have certain structure to push some end-stops (I will explain in the next section). Solidworks can also simulate the gear motion by gear mate. You can check this tutorial to learn how to do it.
  3. The gear mechanism was the only part that I designed inside out, which provided me the possible dimension of the lens. I then modeled the housing for the motors/shutters and also a motor mount for gripping the motor. (I ended up combining the housing with the helmet body to make things clearer and simpler.)
  4. The shutters and the gear mechanism extend to the lens design, which comprises a less chunky lens hood (I somewhat reference it from this lomo camera,) a lens plate and a pair of lens rings. Below the lens plate hides a miniature LED and a hacked webcam, which actually used for image capturing.
  5. Then, it comes to the body design, and I separated the body to three parts – top, mid and bottom.
  6. The top houses an off-the-shelf flashlight and the batteries. In order to ensure the top is rigid enough, I added ribs to strengthen the structure.
  7. The mid part is another complicated part. The one you see is the latest version. At the front, it directly houses the shutters, which locked by two pairs of setscrews. The helmet mid also houses the electronics and the back LCD. I added eight ribs at the corners to strength the structure – four at the top are for mounting a hat like things from the inner part of an industrial hard hat, which I will show in the next section. The inner walls have some hooks for routing the cables.
  8. The bottom part follows the structure of the mid and I added filets to shrink the volume and visually balance with the top.
There are more models I had to make as you can see from the exploded view. Then I prepared the .step file and BOM (bill of material) and send to China for the CNC process. For a complex builds that embeds mechanical function, it might easier to pay a service which could build and evaluate in 3D modeling, and have a fabricator produce it by machining like CNC or 3D printing. I found a few Chinese companies that make high-end prototype for later master mold and mass production, some they take single or low quantity orders. The advantage is they always have good turn around time and offer affordable deal, the down side is that shipment is required for back and forth evaluations. If you don't live in China, don't speak Chinese or require multiple revisions this can be costly. Luckily there are a number of businesses that are set up international for this, made-in-china.com or alibaba.com might be helpful.

Step 4: Mechanical and Electronics Design

After the parts have been manufactured it's time to combine the physical product with the electronics and mechanics. Usually parts will fit as you designed, but sometimes you have to trim the object a bit to join things. I sent over matching components to the manufacturing company so that they can reference them at post-production, eliminating possible misfits.

After I assembled the shutters and motors I did a mechanical test. Luckily, the gear simulation in Solidworks didn’t disappoint. You might see there are some snap switches at both ends of the gear, they are called end-stop and are an important element when you use a stepper motor. Though stepper motors can do very precise movement like when used for driving CNC machine, they don’t actually know their position as servomotor do and they never know if they have actuated something to the end all not. End-stop is a switch (sometimes optical switch) that moving part hits at the end of a motion to determine if the part has reached the end (or the start.) For example, when a scanner starts up you can always see the scan bar is moving towards the bottom (or top) of the scanner, such action reset the scanner and make sure it starts scanning from the start location.

The motors are driven by a pair of stepper motor drivers that take commands from an Arduino Nano, which also takes the end-stops signals and touch sensor signal as well as controlling the front LED, LEDs for lighting up the wearer’s eye (because the eyes are too dark to be seen when covered by the helmet) and the flash light.

The image capturing and displaying are done by a Gumstix, which communicates with Arduino to receive the data of touch and to time the image capturing.

The entire system was tested in a perfboard with a custom circuit. After confirming proper operation on the perfboard I used Eagle to design my PCB and produce the printed circuit board from China. Seeed Studio produces pretty high quality board at a nice price and turn around time with very user-friendly ordering system (take order/communicate in English as well.)

Step 5: The Touchswitch Sensor Research and Experiment

Unfortunately, the touch sensor is still under research and development, and I cannot share the current model. Our goal of the research is to have the sensors interact with the environment such that: 
  1. People can touch me anywhere (skin) to interact.
  2. People don’t have to hold/attach to any device when touching.
  3. The sensor has to be portable, so the wearer can move anywhere.
We are still researching existing technology that can fulfill all these requirements. We are currently experimenting with the theory of Theremin, capacitive sensing and radio transmission. If you happen to have some suggestions, please let me know!

Regarding the difficulty of the research, I am now creating an intermediate (touch sensing) version of Touchy which relies on a very simple technology as using human bodies to complete a circuit with transistor, this video shows how it works. The down side is, the user has to hold something before touching me, but at least it can kicks start the social experiments!

This is a quick summary of the project. I hope you enjoy it. Please comment and let me know what you think.

Stay in touch with TOUCHY!!!