Recent Advances of 4D Printing Technologies Toward Soft Tactile Sensors

Abstract

Soft tactile sensors (STSs) combine the flexibility and the converting ability between mechanical forces and electrical signals. 4D printing was first introduced in 2013, and attracted great interest because of its versatile functionalities in actuators, artificial muscles, STSs, soft energy harvesting, pneumatic nets, electroactive polymers, and soft electronics. Using the 4D printing concept to fabricate STSs is promising, yet it is at its infant stage. At present, researchers have utilized two types of strategies: one is directly using smart materials through 3D printing manufacturing, and the other is programming codes of components and structures to create controllable changes. This review summarizes the recent research on 4D printing toward STSs and discusses the future perspectives of this emerging field.

Additive manufacturing of smart polymeric composites: Literature review and future perspectives

“…[32] However, the bio-responsiveness of material is best contemplated by its potential to agree with the microenvironment and stimulating signals to activate cellular reaction, best demonstrated by piezoelectric materials. [261] Piezoelectric materials are intelligent materials that can trigger an electrical response by altering the mechanical deformation, [262] as shown in Figure 18. However, other techniques can accomplish the same objective as electromagnetics and electrostatics, which are surpassed by the piezoelectric materials due to their effective performance and intense sensitivity.…”

“…Piezoelectric materials are intelligent materials that can trigger an electrical response by altering the mechanical deformation, [ 262 ] as shown in Figure 18. However, other techniques can accomplish the same objective as electromagnetics and electrostatics, which are surpassed by the piezoelectric materials due to their effective performance and intense sensitivity.…”

Novel Copper Complexes as Visible Light Photoinitiators for the Synthesis of Interpenetrating Polymer Networks (IPNs)

“…The elaboration of polymers by photochemical means, such as free radical photopolymerization (FRP) and cationic photopolymerization (CP), have been mainly based on the use of metal-free organic dyes and photoinitiators at the industrial and academic levels [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ], and these synthetic processes (FRP and CP) are widely used in different fields, e.g., dentistry [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], adhesives [ 24 , 25 , 26 , 27 , 28 ], coatings [ 29 , 30 , 31 , 32 , 33 ], composites [ 34 ], medicine [ 35 , 36 , 37 , 38 , 39 , 40 ], direct laser write, 3D and 4D printing [ 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 ], etc. On the other hand, organometallic compounds are not really used in industry; in other words, manufac...…”

Industrial Digitalization with Four Dimensional (4D) Printing - Novel Technology: Brief Review on Developments, Challenges and Applications

“…Plastic deformation is a vital role in the printing, it is a material property exposed to heat and cannot retain its original shape after forming a solid structure. Some materials found from the literature having special properties such that when such material exposed to heat, light, moisture and water they change its structure and also modify the shapes [1,2]. The market experts say that production industry will change its methods of making parts in the next 10 years as follows new practices that are abandoned towards sustainable to eco-friendly environment, flexibility in the design and efficient technique to machine the parts.…”