A technique is exploited to develop a dry ECG sensor using polydimethylsiloxane (PDMS) with enhanced adhesion to skin. The sensor consists of silver nanowires (AgNWs) embedded in PDMS. The adhesive solution presented is a novel technique which combines using high‐ratio 25:1 PDMS selectively deposited in a thin layer on the surface of a sensor body that is made from 15:1 PDMS. With this adhesive mechanism, we demonstrate a cohesive ECG sensor which can adhere to a subject without the use of additional sticky adhesives and that is compatible with current ECG technology. PDMS is residue free and highly biocompatible meaning this is a solution suitable for long‐term wear. We demonstrate that our sensor can be filtered to similar quality of a traditional ECG sensor, and further show that our sensors stay in place for more than 24 hr and it can adhere to skin with an average maximum force of about 1.09 N.

The development of flexible electronic devices has primarily been focused on the production of flat 2-dimensional sensors and has lacked the ability to manufacture devices with complicated 3-dimensional geometry. A mold-based method for manufacturing devices with 3-dimensional geometry that is cost-effective and repeatable is presented herein. This technique is demonstrated by the fabrication of a novel pressure sensor using a 3-dimensional PDMS membrane patterned with a resistive silver nanowire network. The specific geometry of the sensor was chosen to provide a uniform strain distribution along the silver nanowire network. The sensor has a linear response to pressure, a gauge factor of 4–29, and behaves well under repeated cyclical testing. A flat sensor with a 2-dimensional membrane was also manufactured for comparison to the 3-dimensional sensor. It was observed that the flat membrane has a higher gauge factor but has a non-linear response to pressure.

We present an inexpensive, repeatable, and efficient method of patterning silver nanowires onto polydimethylsiloxane (PDMS) using a mold-based approach. A micromilling machine is used to prepare an aluminum mold with a raised pattern so that PDMS cured in these molds is imprinted with the design. A solution of silver nanowires and ethanol can then be injected into the pattern. This method can be used to pattern silver nanowires onto PDMS in any two-dimensional (2D) layout, meaning it can be extended to produce a wide range of PDMS/silver nanowire-based sensors and devices. We demonstrate this by the development of two separate patterns. An intricate logo is developed in order to demonstrate the capability of patterning curved and sharp edges, and a strain gauge is developed in order to demonstrate a functional device.

Laser cutting is often used in the fabrication of Polydimethylsiloxane (PDMS) substrates for novel microdevices such as wearable sensors and microfluidic devices. PDMS is a thermosetting polymer whose material properties are affected by the thermal conditions during the curing process. Since laser cutting exposes the cutting material to high temperatures, this might affect the heat-sensitive material properties. In this work, we examine how laser cutting affects the stiffness of PDMS by measuring the Young’s modulus of PDMS and comparing that to the Young’s modulus of laser-cut PDMS. We find an increase in the Young’s modulus from 0.34 to 0.37 MPa (9%) for PDMS mixed at a ratio of 20:1 base to curing agent. For 10:1 ratio PDMS, we find the increase in Young’s modulus is 31%, from 1.02 to 1.34 MPa.

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