Direct Transfer of Magnetic Sensor Devices to Elastomeric Supports for Stretchable Electronics

Abstract

A novel fabrication method for stretchable magnetoresistive sensors is introduced, which allows the transfer of a complex microsensor systems prepared on common rigid donor substrates to prestretched elastomeric membranes in a single step. This direct transfer printing method boosts the fabrication potential of stretchable magnetoelectronics in terms of miniaturization and level of complexity, and provides strain‐invariant sensors up to 30% tensile deformation.

High-performance giant magnetoresistive sensorics on flexible Si membranes

“…All these tasks are typically solved by means of magnetic field sensorics. In this respect, the smart combination of metallic thin films deposited directly on polymeric supports allowed to fabricate flexible Hall sensors 11 as well as flexible and even stretchable magnetoelectronics relying on the giant magnetoresistance (GMR) effect in multilayers [12][13][14] and spin valves 15,16 or on the tunnel magnetoresistance in magnetic tunnel junctions. 17,18 These flexible devices are already successfully integrated in fluidic systems, 19 applied as pointing devices and proximity sensorics 11,20 and act as components of printed electronics.…”

Shapeable magnetoelectronics

“…Despite the manifold functionalities that are available for shapeable electronic systems, magnetic functionality ( Figure 1) was added to the family of flexible, [67][68][69][70][71][72][73] printable, [74][75][76] stretchable, 43,77,78 and even imperceptible 79 electronics very recently.…”

Compact helical antenna for smart implant applications

“…On the adhesion promoted glass substrate (Methods #1 and 2), we spin coat and photopattern each layer of the functional stack, consisting of a sacrificial layer and a strained bilayer. Here, we apply an acrylic-acid-based sacrificial layer 36 , which offers numerous advantages for further processing, using conventional thin-film and photolithography techniques: this sacrificial layer is stable at high temperatures up to 650°C, inert in common organic nonpolar, polar protic and aprotic solvents, as well as in moderate bases and acids, and photopatternable using standard 365-405 nm exposure sources. The strained bilayer consists of a hydrogel layer expandable in neutral aqueous or alkaline solutions and the polyimide layer, which is chemically and thermally inert and mechanically rigid.…”

“…36 The sacrificial layer solution was spin coated at 3000 r.p.m. for 35 s to produce a 500-nm thick layer.…”