Breathable and Durable Tactile e-Skin Based on S-Shaped Nanofiber Networks by Patterned Additive Manufacturing

Flexible metal-based electrodes with stable resistance and low crack growth rates have important application value in the field of tactile electronic skin, but their breathable performance and durability are at a low level. S-shaped metal nanonetwork electrodes, based on S-shaped nanofiber substrates, are capable of achieving high breathability, excellent electrical properties, and stretch-resistant mechanical properties, simultaneously. Current manufacturing methods of S-shaped nanofiber substrates all suffer from various disadvantages, and they almost all use subtractive fabrications with complex processes and have environmental pollution. Here, in order to prepare durable and breathable tactile e-skin with environmentally friendly, low-cost, and efficient manufacture, a nanofiber-patterned additive manufacturing method is proposed. This additive manufacturing method is based on electrospinning to redesign the collection terminal. Through the design and dimensional optimization of the stacked electrodes, a pronounced electric field gradient forms on the upper surface of the collection terminal. This electric field gradient serves to induce the deposition of nanofibers within the targeted S-shaped pattern area. This one-step additive manufacturing method avoids complex processes, material waste, and chemical pollution, simultaneously enabling nanofibers of S-shaped substrates to have highly integrated structural characteristics. As a result, this durable tactile electronic skin, fabricated by this additive manufacturing method, can achieve sensitive tactile perception while ensuring normal evaporation of sweat on the skin surface and heat dissipation of the body.