To assess whether a vape pen cartridge design is environmentally friendly, consider the following aspects:

1. Material Selection:
   - Check if the vape pen cartridge uses biodegradable materials such as PLA (Polylactic Acid) or PBS (Polybutylene Succinate). These materials have a smaller environmental impact and can naturally break down after use, reducing plastic waste.

2. Recyclability:
   - Assess whether the vape pen cartridge is made from recyclable materials and if the manufacturer offers a recycling program. The use of recyclable plastics and recycling initiatives can reduce the demand for new materials and lower environmental impact.

3. Modular Design:
   - Consider if the vape pen cartridge features a modular design, which not only facilitates disassembly and recycling but also improves production efficiency. Modular design can reduce overall waste as users can replace only the worn parts rather than the entire product.

4. Energy Usage:
   - Evaluate the energy efficiency of the vape pen cartridge during its use. While not directly related to material, efficient energy use can reduce the carbon footprint.

5. Waste Reduction:
   - Consider if the vape pen cartridge design minimizes material usage and waste generation. For example, is there an optimized design to reduce material waste or measures to reduce packaging materials.

6. Circularity:
   - Assess if the vape pen cartridge is designed to be disassembled for recycling and reuse. This can extend the product's lifespan and reduce waste.

7. Ecological Protection:
   - Consider if the production and use of the vape pen cartridge cause ecological damage, such as harming wildlife or protecting water sources.

8. Social Responsibility:
   - Evaluate if the manufacturer has considered social responsibility in the design, such as labor rights and compliance with environmental regulations.

9. Technological Innovation:
   - Consider if the vape pen cartridge incorporates innovative technologies that may bring environmental benefits, such as improved efficiency or waste reduction.

10. Market Demand:
    - Assess the market demand for eco-friendly vape pen cartridges, as high demand can drive manufacturers to adopt more environmentally friendly designs and materials.

By considering these aspects, you can conduct a comprehensive evaluation of the environmental friendliness of a vape pen cartridge.