Taking a page from biology

[Downer]

____Heyo. It's been a long while since I last posted on the forums, so I figured it should be something interesting. So here I am in the Inventor's Corner with an unusual thought. Be forewarned, these thoughts of mine are coming out in a fragmented fashion, so some of them might need further clarification. Please, be sure to ask in your comments.

Proposal:
____The idea is inspired by, and attempts to emulate, the structure of living creatures. Particularly, how the body of an organism is composed of many layers of tissues, the most superficial being the skin, and the most deep being the bone. So, here's a rough breakdown of the approach.


Muscle and bone:
____The first two layers, muscle and bone, would be constructed with the traditional approach we're used to thus far. They would take the articulated skeleton, place it in a mold, and then fill in around it. However, the silicone rubber would be substituted for a much more durable rubber (possibly neoprene, or some kind of gel). This would be slightly more rigid and could take a little more abuse, while still holding its general shape.
____Firstly, this is designed to alleviate some problems of cost and durability. It is my understanding that a good portion of the cost is in materials, specifically how much silicone rubber has to go into making the solid mass of the body. The use of a less expensive material for most of the form limits the silicone rubber to being used where it is really needed (more on that later).
____Secondly, it's well known that a crack forming in the surface of current models is problematic, because it can quickly propagate downward as it tears through the uniform material. With this approach, the innermost material would stop the propagation, limiting it to the surface.
____Finally, this would more accurately simulate the feeling of a real human body by having the slightly more rigid muscles under the skin. The interaction with the skin being very important (more on this later). Also, helping to preserve shape memory of the doll, which silicone rubber seems to have some difficulty managing.


Connective Tissue:
____Next up would be the connective tissue layer. This is achieved by first making sure that the surface of the muscle layer is highly porous. Then, a very elastic rubber is formed around the muscle layer, entering and solidifying in the pores to anchor this layer to the muscle.
____This layer's purpose is to anchor the skin to the muscle. From here, the more elastic material will allow the skin to slide over and be pulled from the muscle, while still keeping it attached. Will also be important in preserving the soft feel (more on this later).


Skin:
____Now for the actual skin, which will itself be composed of two layers. The softer dermis will be the standard silicone rubber that we all know and love. Here, it will be much thinner (thus much less cost) intended to simulate the fat of the skin to impart the soft feel.
____The connective tissue layer's surface will need to be porous like the muscle layer, so that the silicone rubber will enter and anchor to it. This completes the mechanism that allows the skin to slide across the muscle while remaining soft, and returning to its original placement.

____The epidermis will be a thin protective layer on top, that will shield the dermis. This will likely be some form of urethane (not sure).
____One idea I had with this is that by sandwiching the dermis between the epidermis and underlying connective tissue, it might allow the silicone rubber to remain soft, even if it cracks. Specifically, the cracked pieces will be held in place by the two layers, allowing them to remain soft. All the while, the still contiguous outer layer keeps the cracking from affecting the experience.

EDIT: As an added bonus, it might be possible to perform repairs by simply stripping off the skin layer, and replacing it with a fresh one. The underlying shape and structure being largely preserved with minimal loss.


Conclusions:
____That's the long and short of it. How much this plan of mine would save on materials might be negated by the added complexity of assembly. However, part of the idea is to improve the overall quality of the doll, both in terms of feel and durability. How much this approach would actually work would need testing to really quantify (starting with a slab of the material for feel testing, then proceeding to small scale testing, and finally a full model).
____The way I see it though, the current approach of the solid mass around a skeleton just isn't appropriate. It has more than a few flaws that leave it prone to failure, making it a lot of trouble in the long run, despite being easier to implement. So I think at some point, this process will need to be abandoned in favor of a different approach that takes advantage of multiple materials.
____So the way I see it, if we're trying to copy the feel of human, why not copy the design of a human? I'd say that nature has been doing this for much longer than we have, so its design is probably a much better approach. With all that being said, any comments or questions?

[B3F11dolly]

I'd say that nature has been doing this for much longer than we have, so its design is probably a much better approach.

Yes yes this sounds like my friend posting !
Realdoll started about 11 years ago or stuff, the plan of building animals with an outer skin with inner bones [opposite to exoskeleton] can be traced back to the late Cambrian, so let's say 550 million years.

I don't think this will help to reduce the costs of dolly. Yes, silicone is very expensive material, but Thomas from Abyss once said in chat that the cost of silicone is just about 1/10th of the total cost of a doll. Other materials cost money as well, and that will be a very complicated process to construct such a doll, with a lot of work. Actually the costs of handicraft work are the biggest part of the price (along with profit).

Comparing your idea to what nature does, it's pretty close. Human skin has three main layers, that's epidermis, dermis and subcutis (what you call "connecting tissue"), underneath there are layers of muscles and the bones. Epidermis has 2 layers and dermis has 5 layers. As those differences deal with organic functions and how skin renews itself, your approach with epidermis, dermis and subcutis would be just fine.
(I'd even say layers "skin" and "subcutis" would be enough.)

However, I wonder how you're supposed to pour that. The subcutis layer is both anchored in the muscle layer below and the dermis layer above, with its material entering small pores. If you start with the muscle layer, you can pour the subcutis layer onto it and it will anchor, but if that's already poured so far, how to you anchor the dermis layer later on ? Or else if this is one pour, how can you make sure the material will enter the whole space in between of those layers without air bubbles remaining and the material not anchoring correctly ? The next problem I see is that layers of silicone are more vulnerable to tears and marks the thinner they are.

[KawaiiLuvr]

I think thats a great idea Downer. I was actually thinking the same thing the other night. It would make more sense to have the skin be an external layer. Someone here had posted a link to this artist that does plush (gallery work) and it was simply amazing. Some of the photos looked even more real than the Real Dolls. The process had something to do with layering different materials over the surface like skin. I think this might be a good way to go. I imagine it would be cheaper too (if you used a low-cost material for the inner volume).

Other than that, I think mimicking nature is the best bet. If it ain't broke, don't fix it!

[dachemist]

Your approach solves a problem I have on developing a realer touch to skin.

A woman's touch is soft, mostly because the underliying fat and muscle are there, in a silicon doll you can't have such structures, so you average the feel of the three layers.

I found that if you tunnel small pipes under a 1-2 millimeter silicone skin you get a softer and more realistic touch, but didn't knew how to implement that on a doll, (you could "bore" a layer making a mixture of salt (grain) and silicone, but then the end product would look like she had smallpox ), now if you use the "smallpox" layer under a soft pro cured silicone skin...

[newtrix]

[quote="technoguy"]I'm convinced that the future of the silicone love doll will involve greatly reducing the current body weights by a drastic reduction in the amount of the expensive silicone polymer used in the final doll's body.

The simplest way to do this would be to use an expanded polyurethane core. It would contain no skeleton or conventional joints.

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I have been thinking along EXACTLY the same line, EXCEPT using an injection molded hollow PVC core... Your method would probably be even EASIER for the manufacturer to do, and would likely also keep the whole process in house and lower his costs... The current process of using full cast silicone is ridiculous when the weight and cost is considered...

Don't be surprized if some enterprizing Chinese outfit jumps in and gobbles up the market, just as soon as they realize the mass market potential that exists... 'Course they'll also probably end up using some lead based colorant making the thing toxic, and have it banned in the US... The beat goes on!...

[newtrix]

Right now, the Asians seem expert at producing Asian looking dolls with Asian physiques. Well, that is all well and good if the buyer is Asian or a Westerner that admirers Asian females. I'm curious to see what the Chinese manufacturers can do when it comes to replicating the Western female's body and face.

Perhaps in another few years we will be able to see what they can do...
technoguy[/quote]

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Yeah, I think you'd be safe betting the family jewels on it... The BIG question IS - Will they EVER be able to write an owner's manual that we can understand?...

[newtrix]

Interestingly, I noted on their site that one can get a doll with GENUINE pubic hair implanted in its crotch! Wow! That kind of spooks me out. I'd be wondering when I was using the doll if the donor (hopefully a female!) was feeling anything over there in the Orient!!!

technoguy[/quote]

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Yeah, that IS wierd... I like 'em with a smooth lower tummy 'cause that's a fun kissin' spot, but I'll bet that (the bush) is an EXTRA COST option on his dolls... In the Real World ya hafta pay to get RID of it (bikini wax)... Kinda parallel to paying extra for "no salt added" food products...

Many of the Japanese dolls DO have beautiful innocent childlike faces, and would be fun to be around, but the thought of having sex with them is repugnant to me, too... I had three daughters, and have a major soft spot for little girls, so the thought of someone molesting any child makes my blood boil... And in today's cultural climate it's amazingly EASY to be accused or suspected of being a child molester, so NO THANKS, I'll pass on those lovely Oriental childlike dolls!...