Additive manufacturing, commonly known as 3D printing, significantly simplifies the manufacturing process for soft electronics. This work demonstrates the feasibility of a fully 3D‐printed flexible poly(vinylidene fluoride) (PVdF) capacitive temperature sensor. The sensor is constructed using fused deposition modeling (FDM)‐printed PVdF film as the dielectric (thickness ≈180–280 μm) sandwiched between two parallel Direct Ink Writing (DIW) printed silver electrodes (entire device thickness ≈200–380 μm). The motion of the nozzle can facilitate mechanical drawing to the molten PVdF filament, which is a necessary condition to increase the β‐phase content (critical for the sensitivity of the sensor). With optimized printing parameters, the highest β‐phase content (21.30%) is achieved when printing with a nozzle temperature of 200 °C and a print speed of 70 mm s−1. The research demonstrates the application of the device as a temperature sensor by applying heating‐and‐cooling cycles from room temperature (25 °C) up to 140 °C while measuring the capacitance as a function of frequency under different temperatures. The sensor exhibits a stable sensitivity of 3 pF °C−1at 102 Hz and higher frequencies and improved sensitivities at frequencies higher than 102 Hz after dielectric polarization via the corona poling method.
Artificial smart skins that integrate sensing and adaptiveness present a novel platform in wearable electronics on epidermis or next‐generation robotics. Herein, a highly sensitive capacitive touch senor based on a self‐conformable bi‐stable electroactive polymer (BSEP) is developed. The device combines the properties of conformable polymers and touch sensors, which grants the sensor the ability to conform to the shape of various surfaces and in different working conditions. A spray‐coated silver nanowire (AgNW) is selected as the sensor electrode for high‐resolution patterning. The unique antenna‐shaped electrode pattern results in a capacitance change of 31% when in contact with ground at a baseline of 0.13 pF. The BSEP provides stiffness tunability via an embedded compliant heater. The heater combines interdigitated silver with carbon nanotubes delivering uniform and highly efficient heating to create a tunable device with stiffness between 100s of MPa and tens of kPa, providing a large working flexibility. The efficient resistive heater provides uniform and stable heating over an area of 40 by 40 mm with a rate of 48 °C min−1at an input voltage as low as 7 V. This research merges intelligent polymeric systems and thin film electronics advancing conformable, skin‐like functional electronics.
- Award ID(s):
- 1700829
- NSF-PAR ID:
- 10114102
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Intelligent Systems
- Volume:
- 1
- Issue:
- 5
- ISSN:
- 2640-4567
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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