Smart wearables are becoming ubiquitous and witnessing revolutionary developments each day, fueling a multi-billion-dollar industry. From
medical wearable devices to collect diagnostic data, smart tattoos that track sunlight exposure, to smart insoles that monitor your footsteps, technological advancements are pushing the boundaries of wearable innovation. As the wearable industry is still relatively young, functional printing professionals including technical printers, designers, engineers, and system integrators are constantly working together to investigate new processes, materials, technologies, and testing methods.
Aside from the dominant world of smart watches, there has been significant growth and interest in smart medical wearables, clothing, electronics, and sensor solutions. But what are some of the common considerations when developing a new smart wearable?
生物相容性：
由于大多数可穿戴设备
都与皮肤直接或紧密接触，因此生物相容性对于确保用户安全至关重要。根据设备的预期用途，可穿戴基材和结构层中的化合物可能会暴露在汗水、雨水、湿气、防晒霜和驱虫剂中。全面了解各种外部因素的相互作用对于消除不必要的风险（例如皮肤过敏、过敏反应和刺激）至关重要。虽然没有规范所有可穿戴设备的生物相容性的行业标准，但 ISO 10993 为
可穿戴医疗设备提供了一个框架。
电源管理：
有效的电源管理仍然是开发可穿戴解决方案的一大障碍。薄而紧凑的电池通常意味着电池寿命更短，公司一直在努力延长设备的电池寿命，使其至少持续一个使用周期。虽然在使用小型轻便设备时空间是一个巨大的限制，但公司正在通过使用太阳能电池或利用佩戴者的身体运动和体热为电池供电来收集能源。公司正在积极地将 Wi-Fi 连接与蓝牙通信模块进行交易，以实现高效的功耗，并通过电感器转向无线电源。对于大多数用于长期使用的可穿戴服装，电池必须易于更换或充电。
柔韧性和可拉伸性：
智能可穿戴设备，尤其是服装，容易受到很大的拉伸。柔性是可穿戴设备的基本外形尺寸，这使得柔性印刷电子产品成为人们积极寻求的替代品，以替代缝制在服装中的昂贵银线和纱线。根据最终应用，可穿戴基材需要在柔韧性、可拉伸性和稳定性之间取得适当的平衡。除了试验新基材外，该行业目前正在利用医用级材料，包括聚醚基热塑性聚氨酯 （TPU）、聚酯基 TPU、聚对苯二甲酸乙二醇酯 （PET） 以及氨纶、尼龙、弹性纤维和棉等织物。功能性油墨通常印刷在柔性基材上，当用户穿着或随着服装移动时，会发生一定量的拉伸。因此，油墨需要表现出可接受的电阻变化，并具有可重复的拉伸和恢复周期。
密封：
Conductive epoxies, typically used to apply components on to circuits, are often not a feasible solution when dealing with wearable applications as they tend to break under stress. Due to this, applying additional components such as surface-mount LEDs and active PCBs can be challenging. The ability to incorporate electronic components smoothly into apparel whilst ensuring strong adhesion during bending, creasing, and flexing is key to the success of smart wearables.
In addition, smart and medical wearables intended for long-term use must be safe to submerge under water without damaging the circuitry, and physically endure multiple wash cycles. Achieving a water-tight seal and protecting the power source from environmental factors is vital for ensuring optimal performance and durability of the device. For electronic equipment, Ingress Protection (IP) rating specifies the degree of protection from solids and liquids including dust and water. Whether it is fusing stretchable materials with thermoplastic-adhesives backing or applying hot-melt adhesives to polyester circuits, thermal bonding is one of the most common sealing approaches in wearable solutions. Pressure sensitive adhesive (PSA) lamination is another approach that requires a medical-grade adhesive to apply a patch directly to the skin of the user. TPU overlaminates, printable insulators, and PET overlaminates are often used for sealing and potting.
The wearable technology industry is migrating towards a “smart system”, a world where all devices from head to toe communicate with each other to create a single ecosystem. As existing technologies and processes evolve, new norms, standards, and specifications for the industry will gradually develop. With a promising future in sight, the widespread adoption and integration of smart wearables in our daily lives will continue to grow.
Boyd has years of experience creating custom smart wearable solutions. To learn more or discuss your project needs,
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