Design, manufacture, and evaluation of traction features on sprint footwear using laser sintered nylon-12 sole units

Abstract

A novel method for incorporating traction features within sprint shoe sole units using laser sintered nylon-12 was investigated. The design, manufacture, and mechanical testing of the sprint shoe sole units are detailed. Three proof-of-principle concept sole units, incorporating traction features typically embodied in commercially available sprint shoes, were developed and manufactured using laser sintered nylon-12 and assembled with standard sprint shoe uppers. The traction properties of both commercially available and laser sintered outsoled sprint shoes were tested on a bespoke rig. Under the prescribed testing conditions, the laser sintered outsoled sprint shoes compared favourably with the commercially available sprint shoes, with the laser sintered concept shoes generating mean peak traction forces to within 15 per cent of those exhibited by an individual commercially available sprint shoe. The results indicate the potential to create a fully functional sprint shoe sole unit using laser sintering technologies, and thereby to create one-off sprint shoes for athletes, is viable in terms of the shoe being able to provide traction levels close to conventional sprint shoes. However, as the strain rates encountered during sprinting are considerably higher than in the test methods implemented, further human performance testing is recommended.

Is additive manufacturing improving performance in Sports? A systematic review

“…While badminton has had three publications investigating the use of AM for shuttlecocks, these publications were produced by the same authors between 2013 and 2015, [33][34][35] indicating that research on this topic has not extended outside of a single research group. Running/walking exhibits a similar trend, with the ten publications produced by four distinct research groups: Salles et al are responsible for five of the publications investigating insoles, [36][37][38][39][40] Vinet et al have three publications on sprint shoes, [41][42][43] and the remaining two publications are produced by individual research groups investigating AM of vortex generators on running apparel 44 and AM of insoles. 45 The four articles within the sport of cycling are from discrete research groups.…”

“…As a result, research findings have not been validated by multiple research groups, and concepts have not been developed by many different researchers to build a body of evidence supporting the use of AM for a particular application. The extent of testing within the literature also suggests the development of sports products for AM are preliminary concepts, with several studies resulting in critical failure of parts, 42,43,52,53,57 while some studies featured a single sample for testing (although may have included several iterations for simulated tests). 34,35,51 In order to reach the level of acceptance and innovation experienced within the medical industry, consistent and ongoing research is required by sporting product designers within academia and industry, and value must be placed on funding research that may improve the safety, comfort and performance of athletes at all levels of competition and recreation.…”

Designing through craft practice: A woven textile approach for footwear

“…They are relevant to academia within three distinct areas of design research, woven textiles, footwear and craft-based design. In footwear, current research commonly focuses on efficiency (Antemie et al 2012;Joneja and Kit 2013;Liao and Jiang 2008;Maurtua et al 2012) and/or function and performance (Davidson 2012;Head and Porter 2011;Sterzing et al 2013;Vinet and Caine 2011) and is commonly conducted within the sciences and engineering. In contrast, this research contributes a creative perspective.…”

Impact of exercise footwear features on middle-aged and older adults' lower limb muscle activity during gait

“…Advantages noted by Chua et al [162] include the use of wide range of processing materials like nylon, polycarbonates, metals and ceramics compared to photo polymers mentioned in the previous two techniques, no need of support structures unlike previous techniques, etc. Drawbacks of this process include poor surface finish, relatively large size of the printing unit, high power consumption and lower density of the resultant material owing to the use of powder [162,166] In Vinet and Caine's article [168] on sprint footwear, they noted that laser sintered nylon-12 sole 'compared favourably' to other commercially available sprint soles during traction tests. Toon et al [169] used LS technique to manufacture variants of the same footwear with varying bending stiffness to assess the effect of footwear stiffness on human performance.…”