Stretching mode deformation analysis for an elastomeric encapsulation-assisted stable flexible electronic substrate

Abstract

The substrate plays an important role in flexible devices and sensors. In this direction, it is observed that elastomeric encapsulation assists the sensor system to deform successfully under stretching. The encapsulation not only makes it flexible but also protects it from environmental factors and mechanical damage. In this paper, a Finite Element Method (FEM) analysis is used to study the mechanical effects on the encapsulated system, which provides insight into the design of a stretchable substrate for flexible electronic systems. Here a serpentine silver electrode is designed on a PET (Polyethylene Terephthalate) substrate, which is then encapsulated by PDMS (Polydimethylsiloxane). With the variation in the ratio of top to bottom encapsulation thickness i.e., Ten1: Ten2, the interfacial stress was studied. The mismatch in Ten1 and Ten2 may result in compressive bending strain, which can be avoided by making Ten1 = Ten2. It is observed from the simulation that, there is a spike in von-mises stress at the interface of the substrate and the encapsulation when stretching mode deformation is applied. Also, this maximum stress varies with the variation in encapsulation thickness. For a range of total encapsulation thickness i.e. TEN = Ten1 + Ten2 = 30 µm to 100 µm, the optimum thickness is found to be 55 µm, for which the spike in interfacial von-mises stress is minimum.

Engineering mechanical compliance in polymers and composites for the design of smart flexible sensors

“…Furthermore, elastomeric encapsulation for flexible electronic systems is suggested to have a substrate that is more stable towards stretching deformation and protected against mechanical and electrical disturbances. 2 These systems are more flexible and protected from mechanical damage and The study concentrates on a polydimethylsiloxane (PDMS) encapsulated serpentine silver electrode on a polyethylene terephthalate (PET) substrate. According to the study, it is essential to keep the top-to-bottom encapsulation thickness identical (T en1 = T en2 ) in order to prevent compressive bending strain.…”

“…Furthermore, elastomeric encapsulation for flexible electronic systems is suggested to have a substrate that is more stable towards stretching deformation and protected against mechanical and electrical disturbances. 2 These systems are more flexible and protected from mechanical damage and environmental factors due to elastomeric encapsulation. The study by Tripathy et al investigates the mechanical impacts on the encapsulated system using finite element analysis.…”

“…The study by Tripathy et al investigates the mechanical impacts on the encapsulated system using finite element analysis. 2 Fig. 3(a) shows a typical encapsulated substrate and the interfacial stress development due to stretching mode deformation.…”

“…In this regard, engineered polymer materials play an important role in the development of flexible sensors. 1,2 The application of such flexible sensing systems can largely be witnessed in robotics, automation, and healthcare fields. Regular health monitoring of hospitalized patients, patients with chronic diseases, mass screening in the case of a pandemic, or healthy persons for precautionary measures demands innovations in the field of wearable and flexible sensors.…”

Simulation Study on Temperature and Stress and Deformation on Encapsulated Surfaces under Spray Cooling

“…With the development of science and technology, the degree of integration of electronic equipment is getting higher and higher. Heating power has increased rapidly [1,2], resulting in a sharp rise in heat source temperature [3,4]. Excessive temperature can cause the stress of the encapsulated structure to increase significantly.…”