## 1 Introduction  
Because of the viscoelastic characteristics of soft tissue and the low friction between the clamp material and wet soft tissues, it was hard to hold them properly at in vitro loads and at the required loading speed. Excessive compression on the soft tissue will elevate stress around the contact area, which leads to rupture before the target loads are achieved. Less compression will result in slippage [1]. The first successful attempt to prevent such problems has been solved with the \"cryo-jaw\" clamps, as presented by [PERSON] and [PERSON] [2]. They used clamps made of brass connected with four M8 screws to compress the tendon ends, followed by freezing via the circulation of liquid carbon dioxide. [PERSON] et al. [3] applied a similar method on the quadriceps and Achilles tendons without slippage and with no apparent compression problems. [PERSON] et al. [4] used water in the containment chamber, and then (after waiting for the water to be frozen) proceeded with testing of the human quadriceps tendon-bone complexes and patellar ligament-bone complexes. Due to complex freezing equipment, other researches have reported some different solutions. [PERSON] and [PERSON] [5] have presented the nonfrozen serrated jaw clamp made of serrated plastic material. [PERSON] et al. [6] have reported that their new type of nonfrozen tendon clamps could sustain the targeted tensile force of 4.0 kN by holding the tendon firmly without any slippage, with a maximal sustainable tensile force as high as 6.87 kN. This new type of clamp is easy to manufacture and use, as it is small in size and cheap in cost. It can be a good alternative to the complex frozen clamps in the biological simulation tests of muscular activity in musculoskeletal systems. [PERSON] et al. [7] tested and evaluated several gripping methods, including a serrated jaw, sandpaper, frozen ends and air-dried ends on 1 kN Shimadzu pneumatic grips. They have found that by using the pneumatic grips with the cardboard lining, the stress concentration at the grip-specimen interface reduced substantially. By reviewing the available literature, the necessity for existing laboratory equipment to adapt in order to properly execute tissue experiments was also noticeable. [PERSON] et al. [8] reported slippage as a major issue during the tests using the original machine clamps. For a biomechanical comparison of quadriceps and patellar tendon grafts, [PERSON] et al. [9] used the cryo-grips attached to the linear actuator of the MTS servohydraulic test machine (MTS Systems, Eden Prairie, MN). The cryofixation device with its water containment chamber mounted on a universal testing machine (Instron Model 1270, Loadcell Instron Model 2518, High Wycombe, Bucks, UK) is reported in [4]. More such device variations can be seen in [10; 11; 12]. The existence of slipping and rupturing problems, in addition to the lack of standardization, different testing protocols, and custom-made testing devices were the motivation for our study. We investigated whether there was any mechanical engineering field that could help to solve these issues. To our knowledge, there is no such study presented in the available literature, since most of these prior studies were based on customization. Additive production is the process by which a product is made by adding material layer by layer based on data from 3D models. It is considered one of the key development technologies, providing new approaches to production and providing the finished product relatively quickly. It allows us to make very complex geometric products that would be very difficult to create with classical procedures. Current advancements in tissue engineering and regeneration, therapeutic delivery, medical device fabrication and operative management planning ensure that additive manufacturing will continue to play an increasingly important role in the future of healthcare [13]. Currently, fused deposition modeling (FDM) 3D printing is the most popular method for the fabrication of polymer composites.