The rpsexdoll modular eye assembly allows for a replaceable structure with 22 to 30mm diameters. The magnetic interface can provide a suction force parameter of 0.8 to 1.2N and be disassembled in 5 seconds (using a special crowbar tool that is needed, with a contact surface hardness ≥60HRC). According to the RealDoll 2023 Technical White Paper, the replacement cost of the six iris modules (curvature radius 12.5mm±0.02mm) in the standard version is $80-150 per pair, and the lead time for custom 3D printed resin eyeballs (layer thickness precision 0.05mm) is 7-14 days. In the process of operating the key operations, note the silicone eye socket thermal expansion coefficient (CTE 280×10⁻⁶/℃). If the ambient temperature is below 15℃, use a 40-45℃ hot air gun to preheat it for 3 minutes to soften it before operating to avoid over 4N pulling force and eye socket cracking.
Materials engineering solutions bring more possibilities. The soft eyelids of UV-cured silicone (Shore A hardness 5±2) can be reshaped and remodeled by molds to change the height of the eye fissure (within 8-12mm), and the curing only takes 90 seconds (wavelength 365nm, power 30W/cm²). At CES 2024, DollTech launched the smart dimming iris module with a 128-step LCD zoom lens that is capable of switching pupil diameters (2.5-7.5mm) in 0.3 seconds and with a power consumption of 0.8W. Yet there needs to be attention given to the EMI compatibility of the electronic parts – while the rpsexdoll head heating system (15W) works in conjunction with the smart eyeball, there must be provided electromagnetic shielding attenuation ≥30dB (frequency 30MHz-1GHz).
Reverse engineering technology achieves precision matching. Following the three-dimensional data of the prototype eyeball being captured by the EinScan HX handheld scanner (precision 0.03mm), the topological structure was optimized using Geomagic Wrap software, and the assembly gap between the new eyeball and the orbit could be within 0.1-0.3mm. Industrial cases show that to repair the damaged eyeball of a certain limited edition rpsexdoll (produced in 2018), after CT scanning reverse engineering, 3D-printed cobalt-chromium alloy iris stent (wall thickness 0.2mm) successfully restored the original texture, with surface roughness Ra value reduced from 0.8μm to 0.2μm, but the cost per piece was up to $2200.
The dynamic expression system upgrade adds a new dimension. The rpsexdoll third-generation eyeball drive module is equipped with 12 micro servo motors (torque 0.25N·m) that can adjust the eyelid opening and closing speed (0.1-1.2 seconds each time). In combination with the pupil focusing algorithm, it can simulate the vision change of 0.5-5.0 diopters. 2023 user research shows that dynamic system products command a premium of $3,200, but the secondary repair rate has dropped to 4.7% (18% for static eye systems). Japanese Kawaii Tech bionic scleral material (oxygen permeability coefficient 150DK) has extended the continuous wearing time of colored contact lenses from 8 to 72 hours, and the light transmittance is more than 92% (for comparison, when using common materials, it drops to 83% after 72 hours).
Conformity to the law must be closely followed. EU RoHS certification requires that the lead content in eyeball materials must be ≤0.1% (by weight). One Chinese vendor was fined €500,000 in 2022 for using cadmium-containing pigments (0.3%). The United States FDA demands the deviation of artificial eyes’ light transmittance to be less than 5%. The rpsexdoll custom service needs to provide an ISO 13485 certified test report (with 8 biocompatibility tests). Historical dispute cases show that unauthorized reproduction of iris patterns (e.g., the pupil information of celebrities) can result in copyright compensation of more than $150,000 per case. It is recommended to choose open-source designed iris databases (e.g., the 2,000 free templates of the OpenEyes Project).