"Collagen-based, it was crafted to feel exactly like that of a human."...Walter is made of DNA.

Ingeniero
MemberPraetorianJul-02-2019 4:20 PM"Collagen-based, it was crafted to feel exactly like that of a human."...Walter is made of DNA.
"Reaching out she touched his face, feeling the synthetic skin. Collagen-based, it was crafted to feel exactly like that of a human. There was indisputable affection in the gesture. Equipped as he was to instantaneously analyze human expressions, vocal tones, and just years, the effect on Walter could almost have qualified as embarrassment. Designed to deal with almost any conceivable situation, he had no idea how to react to a moment of Genuine intimacy."
Alien: Covenant novelization, page 223.
Collagen
"Where is collagen found?
In nature, collagen is found exclusively in animals, especially in the flesh and connective tissues of mammals. Collagen is a part of the connective tissue that in the skin helps in firmness, suppleness and constant renewal of skin cells. Collagen is vital for skin elasticity.
Ligaments are another type of connective tissue that attach two bones and consequently hold the joints together. Tendons are similar but different type of tissue that attach the muscles to the bones. All of these tissues, the bones, ligaments, tendons and the skeletal muscles themselves, are made up of proteins. One of the most predominant proteins is called collagen.
Collagen is the main component of connective tissue, and is the most abundant protein in mammals, making up about 25% to 35% of the whole-body protein content.
Collagen helps to give strength to various structures of the body and also protects structures like the skin by preventing absorption and spreading of pathogenic substances, environmental toxins, micro - organisms and cancerous cells. Collagen protein is the cement that holds everything together.
Collagen is also present in all the smooth muscle tissues, blood vessels digestive tract, heart, gallbladder, kidneys and bladder holding the cells and tissues together. Collagen is even the major component of the hair and nails." (source)
Collagen Scaffolding
Walter appeared to have collagen scaffolding throughout his framework.
"As a natural material, collagen is ideal for these biomimetic applications. By shaping it into porous structures, collagen acts as a ‘scaffold’ on which cells and tissue can grow in three dimensions in predetermined forms, mimicking those found in the body." (source)
The below image of Walter's arm was filtered like the above images to bring out the detail in the apparent collagen scaffolding.
In the Meet Walter promotion, DNA is mentioned in the customer disclaimer, below, "Matchmaking interview and DNA screening required."
Walter's collagen-based tissue is grown, below.
Before:
After:
Additional details: Walter's body temperature is quite different from a human and Walter clarified he doesn't "feel", a human insecurity.
Both of these concepts are touched on in Phobos, below.
Constructs
In Prometheus: Fire and Stone, the Construct Elden is tended to "medically" by his Francis. Francis later convinces Elden to allow him to inject the Construct with black goo mutagen.
The black goo mutagen has an affect on Elden due to the DNA component in his makeup, below.
Page 223
I believe that it is no coincidence that the "collagen-based" revelation is on page 223 of the Alien: Covenant novelization and the number has meaning, below.
LV-223 is where the story took place in Prometheus: Fire and Stone.
It is reasonable to expect an Elden-like reaction from Walter if his DNA component is infected with the mutagen. This assumption may tend toward "why" Walter was introduced and where the story will go with a collagen-based synthetic (LV-426?).