Here we will discuss making your robot look real. We may touch on the topic of “uncanny valley” which is a term which refers to the consideration that was held for decades that if you make your robot look too realistic that it will be “creepy” to look at.
So lets talk about the skin of a robot.
If you want a robot to look like an old fashion robot then you can forget about skin and just let it all hang out….the plastic hard shell body with the block head and flashing eyes and the block feet.
But if you want it to look like a person, or an animal or a vehicle then you have to try harder.
Lets just talk about the human looking robots here and leave the scaly or furry animal or dinosaur characters to later.
Now before you create the skin you must decide how large the robot will be and decide how much will be covered by clothing or hair and if there must be movement in the hands/fingers or arms or legs and face.
Starting with the head you are dealing with skin that will go over top of the robots electronics and must allow for easy removal, heat dissipation, movement of the eyes/mouth/eyebrow/neck etc.
You can get a realistic dummy head and carve out the back and put the elecronics in or you could add a latex or rubber preexisting face to it or make a special face mold if you have the talent or hollywood effects connections.
We will shortly talk about the type of latex you can buy to make molds but first consider the idea of using a mannequin head like from the Donco hair stylists company and gut the insides like you would carve a Halloween pumpkin.
They are less than full size you must allow for that or get some other head from somewhere.
Some heads can be taken off things like Gemmy Dancing Santas/Halloween Mike Meyers or from a WowWee Elvis Alive or Monkey Alive toy (which sell used for $300 and up).
The Gemmy heads are generally 20 years old and were made in hard plastic or had rubbery skin which looks more realistic. The old English butler has an incredible realistic looking head with moving eyes and head.
You can take many of the heads off certain 5 foot Gemmys like the Santa and the Freaky Geek Monster Frankenstein and plop the head exactly ontop of the moving mechanism.
Be prepared to get out your electric dremmel saw to hack open the back of your Gemmys head to install more electronics to make the eyeballs move if they don’t already. Some are made with flashing lights which takes away from the realism so I would recommend replaced the existing eyes with ultra realistic ones and make them movable with an Arduino microcontroller left/right and updown.
Now of course you can go to the French site of InMoov and get the files to 3d print every part of a humanoid robot and use it as it or add skin to it if you wish. http://inmoov.fr
Now if you must add skin to an existing robot you should start by checking sites like WISH or Ebay for existing masks of people. You can find incredible looking masks of old/young men/women with realistic hair for $30. Or famous poloticians for $15.
So if you really want to get custom then you are talking about working with possibly toxic rubber and latex chemicals and basically learning how to be a special effects artist.
Most people should just hire a professional hobbyist in their local arts scene to do this unless you are really highly motivated.
Check out this video showing the skin work by a Hollywood special effects artist Thomas Floutz. The skin is apparently opaque (not see through) latex and then is airbrushed with layers of oil paint, silicone, calking and solvent. Hair is usually inserted by hand for eyebrows, scalp, beard etc. https://www.youtube.com/watch?v=DAF5lN4SCaM
Some of the best sites to learn more about making skin masks are these ones:
- Lets define the difference between latex, silicone and rubber masks.
Some talk about foam latex which is not as durable as other materials but is used quite a lot in characters that just sit there but they do not age well if they are moved alot.
There are silicon masks which are excellent and companies can even add special mesh to them to make them stronger where there is more movement like in the mouth and around the eyes.
If you decide to start making and pouring a latex mask you will come to a whole area of science and will learn about words like: vulcanizers, accelerators, thickener, compounder, a balanced curing time, pre-vulc or pre vucanized rubber.
The most common latex product for mask making is called RD407.
Foam latex is a more complicated process and is different than the liquid latex technique which is also called slush casting since you pour liquid latex into a mold and shake it around.
You can go to some of these special effects sites and purchase training videos to work with rubber.
Now the skin goes on the head, hands and any other exposed part of the body that does not have clothing.
Prosthetics makers and expert robotocists will add colorants to their poured latex and will touch up the final product as well in various ways.
Dealing with rubber paint can be extremely toxic so experts should really be involved in this.
Some involve oil based paint and rubber cement paint.
A safer approach to painting the skin is to use an older paint called PAX paint.
Another skin maker uses s product called Psycho paint and dragon skin 10 platinum silicone.
You would paint the silicone with various silicone pigments. Silicone plus krylon silepig.
Check out this excellent Youtube video by the user The Dark Power on making masks with Silicone. https://www.youtube.com/watch?v=WloiHzlwt1s
There is a good discussion of the topic of cleaning the silicon skin on a robot be it a robot used as a healthcare aid in a medical environment or as a companion or possibly love robot. https://hackaday.com/2021/08/25/welcome-to-our-new-robot-nurses/
One owner of a silcone skin doll says that he washes his dolls skin monthly with mineral spirits and adds new mineral oil to the skin to keep it clean and flexible.
Another user on the website commented that silicone does not need oiling but TPE skin dolls do. This person then says that most skins are chemical resistant but that cleaning the crevices in the hands and joints and behind the face where the mechanisms and electronics are would be much harder to clean.
A Youtuber Randi Rain who repairs toy robots on Youtube and does other amazing artistic and electronics offers many tips on working with latex and other repair materials.
Of course there are companies which have been making full size human dolls and now computerized robot dolls for recreational use.
It must be understood that there is a certain quality control issue that one must consider when applying pull on body skin to a robot as there will be wear and tear on any movable part and there could easily be tears anywhere on the robot that will have to be repaired at a cost.
Hanson robotics has created their own special artificial skin called Frubber and companies like theirs are always tweaking their formula to make the absolute best product.
The medical community is always looking for ways to avoid actual medical skin grafting for burn patients and is constantly working on ways to create artificial skin in a medical environment.
If one is to develop the most ultra realistic robot then they must add other features to the skin other than moles and hair and scars and age spots….perhaps they can add a warmth to the touch feature or possibly movement near the wrist pulse area or neck or heart.
The Gemmy animatronic Edwardian Butler 5 foot doll which sells used for $200 has an amazing looking head and eyes which move but also when it plays the sound of heavy breathing, they have a motor near the chest which causes the chest to simulate breathing!
Now lets talk about hair.
If your robots face and body skin and eyeballs have a very realistic look then you better not get too cheap and use acrylic hair.
There is a series of 3 or 4 free training videos explaining the different qualities of hair stylist school practice heads with hair.
They explain the benefit of human hair versus syntethic versus a hybrid.
Some animatronics like the Gemmy Edwardian butler sold two versions of the same character. One was sold with hair attached to the hat so that when the hat was removed the character was bald. The other version had the hair implanted into the plastic.
In some cases you may want to hand install hair into your characters bald head or perhaps into the plastic or rubber hand or parts of the body like the chest or legs of a male.
There is an excellent youtube video by user channel “everything dolls” which shows how to re-root hair into a small toy doll but the concepts and technique can be applied to any mannequin head or body part for a robot.
Now there is almost no end to how far you could go to try to make your robot as realistic as possible.
You will add some type of teeth which you can easily find online and then consider having a soft tongue that will appear moist and will move as the mouth moves.
You could put the motor in the chest to simulate breathing with a simple motor for under $100 so you could certainly add breath to the robot which could fog a mirroR. You could make the robot perform some other human like actions like coughing, spitting, having moisture in the armpits, body odor, an audible and touchable pulse or heartbeat. You could even go all out and simulate some body fluids by running a thin bubble layer of bagged artificial blood on one arm and then poking the robot to show the blood come out like an injury.
So the world of robots can then start to merge more with the special effects and magic show realm where at some point the viewer or witness is not sure if they are seeing a robot or a person at least at a distance.
Making the robot move in a realistic way is difficult and especially to walk without looking like a robot. Then you must make it speak with a human like voice and then eventually if you are expecting it to react to its environment with some vision technology and to answer questions then you need to either have amazing artificial intelligence software and hardware ready or make sure that the questions are all pre scripted and recorded to come off perfectly.