fig4

Figure 4. (A) The multiple neutral planes formation applying low modulus adhesives in integrated structure^[90]. Reproduced with permission. Copyright © 2017 IOP Publishing; (B) The location of multiple neutral planes is controlled by a combination of high and low modulus adhesives in top and bottom sides^[119]. Reproduced with permission. Copyright © 2020 KMEPS (CC BY NC); (C) The strain splitting of rigid layers (orange) occurs well with increasing thickness of adhesives through forming neutral multiple planes^[40]. Reproduced with permission. Copyright © 2016 The Royal Society.