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S. Koteswari and Y. Shivraj Narayan
equipment (PPE), the insoles should possess thermal insulation [27]. 3D printed
arch can be placed at a targeted position on pre-fabricated insole [9]. Latest trend
is with continuous core reinforced filament deposited with a matrix material [28].
Hydrophilic membrane can be laminated to avoid bromhidrosis [15]. Apart from the
manufacturing time 3D printing has advantages like cost of equipment, geometric
complexity, materials, material waste and labour time [6, 18]. To reduce printing
time turnkey process is preferred [30]. The most preferred printer is Fused Filament
Fabrication [13]. Selective laser melting 3D printing is preferred to reduce effective
modulus by 75–80% [22]. Digital Light Projector 3D printing technique hardens
layers by projecting light [28]. MEX 3D printer used for printing TPU and TPE
materials [17]. Dual extrusion 3D printer is used with Poly Vinyl Alcohol as support
material [25]. Selective Laser Sintering, Stereo Lithography Apparatus, Selective
Laser Melting are preferred to print entire shoe [13, 27].
3.1 Materials Preferred for 3D Printing Insole
Depending on the methodology preferred, an insole can be printed with elastic material and support sole with hard material. Fila Flex, ninja flex, soft flexible PLA
are preferred materials [29]. Few insoles use electrically conductive materials like
velostat [25]. For insoles with different densities and porosity polyethylene material is used. Flexible polyurethane material is preferred for good abrasion, fatigue
resistance, good impact and more friction [9, 27]. Monolithic induced matrix materials act as composites [28]. Polylactic acid (PLA), acrylonytrile butadiene styrene
(ABS) preferred to develop base of insole [13, 15]. For high durability, strength and
medium flexibility, polyethylene terephthalate glycol (PETG) is used [11]. For nonslip and smooth surface types of insoles tango plus material is used. For transparent
insoles veloclear material is used [24]. Materials like liquid polymer, polyester is
also preferred for 3D printed insoles [15].
4 Conclusions
Improper foot alignment is one of the major problems which tend to excess plantar
pressure for flat foot patients. Neglecting this would increase severe pain at some
portions of lower limb furthering to misalignment of body. Dysfunctions of the hip,
knee, or even the back therefore may be associated with problems originating at the
ankle or foot. Use of insoles reduces lower limb alignment problems. In teenagers,
flat foot is due to over-weight. Effect of insole on sagittal plane is more compared to
other planes. 3D printed insoles weight is reduced to 25% than traditional methods.
Achilles tendon load is reduced by using rocker shoe hence more preferred for
midfoot strikers. Advanced 3D printing prefers splitting zones technique. Turnkey
S. Koteswari and Y. Shivraj Narayan
equipment (PPE), the insoles should possess thermal insulation [27]. 3D printed
arch can be placed at a targeted position on pre-fabricated insole [9]. Latest trend
is with continuous core reinforced filament deposited with a matrix material [28].
Hydrophilic membrane can be laminated to avoid bromhidrosis [15]. Apart from the
manufacturing time 3D printing has advantages like cost of equipment, geometric
complexity, materials, material waste and labour time [6, 18]. To reduce printing
time turnkey process is preferred [30]. The most preferred printer is Fused Filament
Fabrication [13]. Selective laser melting 3D printing is preferred to reduce effective
modulus by 75–80% [22]. Digital Light Projector 3D printing technique hardens
layers by projecting light [28]. MEX 3D printer used for printing TPU and TPE
materials [17]. Dual extrusion 3D printer is used with Poly Vinyl Alcohol as support
material [25]. Selective Laser Sintering, Stereo Lithography Apparatus, Selective
Laser Melting are preferred to print entire shoe [13, 27].
3.1 Materials Preferred for 3D Printing Insole
Depending on the methodology preferred, an insole can be printed with elastic material and support sole with hard material. Fila Flex, ninja flex, soft flexible PLA
are preferred materials [29]. Few insoles use electrically conductive materials like
velostat [25]. For insoles with different densities and porosity polyethylene material is used. Flexible polyurethane material is preferred for good abrasion, fatigue
resistance, good impact and more friction [9, 27]. Monolithic induced matrix materials act as composites [28]. Polylactic acid (PLA), acrylonytrile butadiene styrene
(ABS) preferred to develop base of insole [13, 15]. For high durability, strength and
medium flexibility, polyethylene terephthalate glycol (PETG) is used [11]. For nonslip and smooth surface types of insoles tango plus material is used. For transparent
insoles veloclear material is used [24]. Materials like liquid polymer, polyester is
also preferred for 3D printed insoles [15].
4 Conclusions
Improper foot alignment is one of the major problems which tend to excess plantar
pressure for flat foot patients. Neglecting this would increase severe pain at some
portions of lower limb furthering to misalignment of body. Dysfunctions of the hip,
knee, or even the back therefore may be associated with problems originating at the
ankle or foot. Use of insoles reduces lower limb alignment problems. In teenagers,
flat foot is due to over-weight. Effect of insole on sagittal plane is more compared to
other planes. 3D printed insoles weight is reduced to 25% than traditional methods.
Achilles tendon load is reduced by using rocker shoe hence more preferred for
midfoot strikers. Advanced 3D printing prefers splitting zones technique. Turnkey