Traditional pressure sensors are typically rigid and distinct from the product casing, limiting product design and form. This lack of flexibility makes creating comfortable and adaptable product casings challenging, stifling designers' creativity.

Invisible is a parametric capacitive flexible pressure sensor crafted through a 3D printing process that combines conductive and non-conductive materials. This sensor seamlessly integrates into the parametric structure and overall product design, offering a perfect blend of customization and integration. This user-friendly approach caters to the convenience of designers and developers.

With the innovative Invisible technology, we've designed two groundbreaking products:

·Gait Monitoring Pressure Detection Sports Shoes:These shoes go beyond conventional boundaries by visualizing gait pressure. Real-time pressure values from physical shoes sync with a virtual shoe model, generating dynamic pressure deformations. This unique fusion not only aids athletes in analyzing foot pressure but also empowers individuals with lower limb disabilities to gain insights into their foot pressure. The virtual shoe model also facilitates personalized shoe design based on individual foot shapes.

·Adaptive Body Posture Chair:Unlike traditional designs that compel individuals to adapt to the product shape, this chair revolutionizes sitting comfort. Poorly designed chairs often lead to incorrect postures and increased lumbar pressure over time. Our chair features real-time pressure detection, enabling precise control over the inflation and deflation of safety airbags. This adaptive technology allows the chair to respond dynamically to the user's posture, delivering enhanced lumbar support and protection over prolonged usage.

Invisible technology, with its flexible and integrated approach, opens up new horizons in product design and functionality, a harmonious blend of comfort, adaptability, and innovation.

To meet the new demands of the era of digital intelligent manufacturing, our design harnesses the characteristics of materials and parametric structures, achieving innovative functionalities of 3D printed dot matrix pressure sensors. The work provides a program that allows designers to quickly generate and manufacture "flexible parametric pressure sensors" of any form; the sensor body is made by 3D printing, a mixture of conductive and non-conductive materials, capable of flexible interaction, realizing the integration of structure and functionality.

Traditional pressure sensors are usually rigid, limiting the product design and shape and lacking flexibility and comfort in the interaction mode. They may restrict the user's operation mode, reduce the interaction effect, and have poor comfort and sensitivity. Their shape cannot be changed arbitrarily, customization is not easy to achieve, and they have low interest. At the same time, the pressure-sensing function and product appearance are separate. Designers usually use ready-made pressure sensors, limiting their ability to exert their creativity fully.

The design uses Grasshopper to make a particular interactive generation program. Firstly, two surfaces are selected, and parameterized filling is automatically formed between the two surfaces. The essential element type of filling can be changed. Then, drag different sliding rods to adjust the position, area and distribution of pressure sensing. Then, the complete model is obtained by the materialization operation. The model file is transferred to the dual-nozzle 3D printer to realize the hybrid printing of conductive and non-conductive TPU materials. Finally, the digitally-customized flexible parametric pressure sensor is obtained.

Based on this design and manufacturing method, two products have been designed:

The Invisible Gait Pressure Detection Athletic Shoes use 3D printing to create flexible parametric soles with pressure-sensing and shock-absorbing features, paired with a virtual end for visualized gait motion detection and shoe customization, improving comfort and durability; the Invisible Adaptive Posture Chair utilizes these sensors and airbag control to automatically adjust the chair surface shape according to a person's posture, enhancing the wrapping feel of the seat, providing more support to the lumbar spine, and alleviating burden.

The sensor has potential and expandability in many aspects, providing a more natural, intuitive, and intelligent interactive experience. There will be very complex application scenarios in the future. For example, in the field of human-computer interaction, it can provide a more natural, intuitive, and expressive way of interaction; in the field of smart wearables, it can provide a more personalized, intelligent, and healthy wearing experience; in the field of pressure ulcer health, it can provide more accurate, real-time, and convenient monitoring and diagnosis services.