Improvement on the softness of the rpsexdoll is achieved on the aspects of material technology, skeletal structure optimization and intelligence. As documented in a 2023 report published in the Journal of Biomimetic Materials, the use of a new thermoplastic elastomer (TPE) and nano-foam silica gel with 0.8g/cm³ density is capable of reducing the Rock hardness from A15-20 for normal silica gel to A5-8 (close to the human skin hardness A3-5), with an increase in the sense of touch verisimilitude by 62%. For example, Japanese DollFantasia launched the “SilkTouch” series, through the gradient density design (surface hardness A5, inner layer A10) to achieve “soft on the outside and tough on the inside”, user research shows that its softness satisfaction is 94% (conventional model 73%). But material costs increased by 28% (from $800 to $1,024 per unit).
Technically, the micro-airbag embedding technology can dynamically control the local softness. RealBotix’s “AdaptiSoft” mechanism embeds micro airbags of diameter 1-3mm into chest and joints, and makes touch hardness float by ±15% using air pressure modulation (0-30kPa range) with energy usage merely 5W/h. Experiments have shown that the technology reduces error in pressure distribution in hip flexion from 18% to 3% in conventional designs, but airbag life is limited by cycle number (12% failure after 50,000), and maintenance cost increases by $150 per year.
Material innovation combined with bionics is another option. The “neuromorphic silicone” created by MIT laboratory in 2024 replicates the human fascia structure (multi-layer fiber mesh density 1200 holes/cm²), and under the condition of maintaining a tear strength of 180% (that of traditional TPE is 100%), the surface elastic modulus is driven to 50kPa (comparable to human skin 45kPa). The US user test shows that the fold reduction degree of its knee socket and elbow socket is 91%, but the mass production cost is as high as 2200 US dollars/unit (traditional model 600-1200 US dollars), limiting market penetration (only 13% of the luxury market).
Market feedback shows that customers are willing to pay a premium for softness but are worried about durability. 2023 Worldwide rpsexdoll sales data show that the price per unit of customers of the flexibility upgrade model increased by 35% (from $2,500 to $3,375), the re-purchase rate increased to 52% (normal model 28%), but the return rate increased by 19%. The main reasons are silica gel delamination (incidence 7%), long-term use after hardness recovery (A3 increase each year) and other reasons. For example, User B’s “UltraSoft Pro” that had its hand hardness increased from A5 to A9 after 6 months cost $300 to repair.
Legal and safety matters: the EU RoHS 2.0 requires new soft rubber material with less than a 0.1% content of plasticizer, while specific ultra-soft TPE (hardness A3) must contain 0.15% phthalates to provide ductility, involving a penalty of 450,000 euros on DollTech in 2023. In addition, the ultra-soft material’s ignition temperature is reduced to 260 ° C of common silicone from 320 ° C, resulting in fire hazard cases (annual incidence rate of 0.7%).
Next generation is on green and intelligent materials. The “EcoGel” Beta 2025 product uses a vegetable water-based polymer (A4 hardness, degradation cycle 3 years) and an electroactive polymer (EAP) for pressure-sensitive softening (response time of 0.3 seconds), yet with a startup cost 2.8 times that of conventional materials. The industry predicts that by 2028, the adoption of neuromorphic chips and aerogel composites can reduce softness error to ±2%, while decreasing the cost of mass production to 60% of current solutions, fueling the premium rpsexdoll market growth rate of more than 24%.