While robotic silicone and human silicone are highly similar in core components and basic performance, their application scenarios lead to significant differences in functional emphasis, safety standards, manufacturing processes, and cost structures. The following comparative analysis focuses on three dimensions: material properties, application scenarios, and technical requirements:
I. Core Components and Basic Performance: Common Source, but Different Optimization Directions
Material Composition
Both are based on two-component addition-type silicone rubber (component A: silicone + component B: curing agent), which forms a soft elastomer through a vulcanization reaction. The core component is polydimethylsiloxane (PDMS), but the proportions of additives differ:
Robotic silicone may contain additional anti-wear and anti-aging agents to accommodate long-term mechanical motion. Some products incorporate conductive materials (such as silver paste and carbon nanotubes) to achieve tactile feedback.
Human silicone emphasizes biocompatibility, and additives must be certified by medical standards such as the FDA and SGS to ensure they are non-toxic, odorless, and non-allergenic. Physical Properties
Hardness Range: Both silicones can achieve a hardness range of 0-50 Shore A through formulation adjustment, but robotic silicones tend to have a medium hardness (20-30 Shore A) to balance flexibility and support. Human silicones cover a wider range (0-18 Shore A) to simulate the tactile feel of human tissue.
Tensile and Tear Strength: Robotic silicones must withstand higher mechanical stresses, typically with a tensile strength of ≥5 MPa and a tear strength of ≥14 kN/m. Human silicones prioritize softness, with a tensile strength of approximately 3-5 MPa and a tear strength of approximately 10-14 kN/m.
II. Application Scenarios: Functional Requirements Determine Material Properties
Robotic Silicone
Core Requirements: Tactile feedback, durability, and environmental adaptability.
Tactile Sensors: Serving as a soft sensor substrate, these materials can be embedded with triboelectric materials (such as PA66 and PTFE) or microneedle arrays to enable multi-directional force detection (for example, the silicone-based soft sensor developed by the UBC team can precisely grasp an egg). Extreme Environment Adaptability: High temperature resistance (-50°C to 250°C), chemical corrosion resistance (such as hydrophobic nano-coating for oily environments), and extended service life up to 100,000 cycles.
Customized Production: Supports 3D printing mold forming, allowing for rapid development of complex structures (such as bionic bone designs and microfluidic tactile feedback systems).
Human Silicone
Core Requirements: Biosafety, realistic touch, and ease of processing.
Medical: Used in prosthetics and rehabilitation devices, ISO 10993 biocompatibility testing must be passed to ensure long-term human contact without rejection.
Adult Products: Simulate the feel of human skin, requiring high elasticity (elongation at break ≥ 500%), low oil release, and ROHS environmental certification.
Film and Television Props: Emphasize color adjustability (such as skin tone and transparency) and detailed reproduction (such as facial wrinkles and vascular texture). III. Technical Requirements: Safety Standards and Manufacturing Process Differences
Safety Standards
Silicone for Robotics: Must meet industrial standards (such as IP68 water and dust resistance and UL94 flame retardancy). Some medical robot applications require ISO 13485 medical device quality management system certification.
Silicone for Human Body Applications: Must pass FDA 21 CFR 177.2600 (food contact grade) and ISO 10993 (biocompatibility) certifications. Some products must meet biodegradable requirements (such as chitosan-based electronic skin).
Manufacturing Process
Silicone for Robotics:
Multimodal Sensing Integration: Through a co-vulcanization process, silicone is combined with piezoresistive and piezoresistive capacitive sensors to achieve simultaneous detection of normal force (0.1-10N) and shear force (±50°).
Miniaturized Packaging: Using sputtered metal thin film reflective layer technology, the visual tactile sensor thickness is reduced to less than 3mm, adapting to the compact structure of robots. Human Silicone:
Precision Infusion Molding: A vacuum degassing machine is used to eliminate bubbles and ensure a surface smoothness of ≤0.1mm for prosthetic limbs and facial molds.
Layered Coating Technology: A multi-layered silicone structure (such as the 25 Shore A DIGIT sensor) balances softness and durability, reducing costs to one-fifth of traditional solutions.
IV. Cost and Market Trends
Cost Structure
Silicone for Robotics: Due to the need to integrate sensors and conductive materials, the unit price is relatively high (approximately 80-120 yuan/kg). However, large-scale production can reduce costs by 60% (for example, 3D printing technology based on digital twins can reduce customization cycles from 2 weeks to 48 hours).
Human Silicone: Medical-grade products are expensive (approximately 150-300 yuan/kg), but standardized production in the adult product sector has reduced prices to 70-100 yuan/kg.
Market Growth
Robotics: The global market size is expected to reach US$47.8 billion in 2029, and silicone-based sensors will cover 90% of the tactile sensing needs of robotic hands. Medical field: The global prosthetic rehabilitation market size will reach 14.3 billion yuan in 2028, and degradable silicone tactile sensors will become a new direction for short-term implant monitoring.