In-mold electronics (IME) have become increasingly popular and mature. Still, most prototypes and applications focused on touch-sensitive surfaces that are not optically clear transparent and thus unsuitable to combine with a display. This year Heraeus, Nanobit, and SigmaSense have overcome this limitation: a transparent, crystal clear capacitive touch sensor, thermoformed into a half-sphere. Two design prototypes will be highlighted at C-Touch 2021: one mounted on a display and another on a mini-LED array. Displays are no longer limited to being simply flat, curved, or bent. Manufacturers can now expand and explore the possibilities with 3D to create human machine interfaces (HMI) with new form factors and designs of virtually any shape to satisfy the creativity and needs of the designers. Automotive interiors and home appliances are promising applications for the new generation of 3D optically clear touch sensors.
The conductive polymers Clevios™ PEDOT:PSS by Heraeus combine all attractive properties for capacitive touch sensors. Touch sensor electrodes can be directly screen-printed or patterned from film rolls that are wet-coated from solution by economic processes. High conductivity and light transmission with perfect clarity and low light reflection are the key features of Clevios. Being organic and polymeric in nature, Clevios™ coatings exhibit high mechanical flexibility and allow for curved or bent designs as well as foldable touch sensors which has been demonstrated during past C-Touch shows. But Clevios™ can do much more than other transparent conductors: thermoforming and stretching while maintaining superior optoelectrical properties.
SigmaSense transformed digital sensing technology introducing a new sensing platform software defined sensing (SDS). SigmaDrive® current mode sensing uses ultra-low voltage signals with many different frequencies, which it sends and listens to on rows and columns simultaneously. The low voltage sensing technology is noise tolerant and eliminates the RC timing constraints that exist with alternatives. SigmaSense controllers enable the use of Heraeus’ Clevios™ conductive polymer technology across the full range of sensor sizes and shapes, including 3D optically clear sensor designs. This industry breakthrough will enable a wide range of human machine interface (HMI) advances revolutionizing devices.
SigmaDrive touch controllers deliver 100-1000X better signal-to-noise per volt compared to voltage threshold mode alternatives. Continuous sensing on each reprogrammable channel provides the big data enabling software defined sensing and provides high fidelity data for AI processing and machine learning applications. This ushers in a host of new features including, high hover non-touch interactive devices, presence detection while providing operation with thick winter gloves, or touch through water.