## 1 Introduction  
Coronary artery diseases are the leading cause of death worldwide [1], which is a compelling reason to continue research to develop methods and techniques for treatment. Among those methods, stenting arteries for dilation has become the standard in battling coronary artery stenosis. The currently available stents are fabricated from non-degradable metals such as titanium, stainless steel, and cobalt-chromium alloys. Devices made of these metals remain permanently in the body and may cause restenosis, impaired coronary vasomotion, and development of early neoatherosclerosis [2]. There is ongoing research to find biodegradable metal stents that can open obstructed arteries, keep them open for a short period of time, but then disappear after the arteries's restructure because then the stents are no longer needed. The absorbable metal should be able to provide mechanical scaffolding and support and absorb in the body without harming the vessels. Typical representatives of biodegradable metals are magnesium (Mg), iron (Fe), zinc (Zn) and their alloys. Some general criteria that have proven useful for qualifying a biodegradable material as useful in stent applications are defined in Supplementary Information, Table S1 [3]. Metallic Zn appears to be one of the few physiologically acceptable metals that has not yet been actively considered for the production of bioassay stents. Zn and its alloys exhibit a wide range of ultimate tensile strengths, varying from 87 to 399 MPa, and elongation to failure values from 0.9% to ~170% [4; 5], so several alloys fit some of the criteria outlined in Table S1. It has been reported, in the same reference, that Zn is more ductile than Mg. Exploring the possibilities of Zn alloys with the appropriate strength, hardness, and ductility will be one of the main goals of future metallurgical engineering efforts. This would broaden the spectrum of uses for Zn and its alloys for biomedical implants. In our study, we propose a new technique, photo-chemical etching, for fabricating stents using pure Zn metal. This novel technique can be extended, in future studies, to Zn alloys that would satisfy all parameters mentioned in Table S1. Another advantage of Zn is its corrosion characteristics. Among the three biodegradable metals, Fe has the lowest corrosion rate, which is too slow for stent applications, and its corrosion products accumulate and are difficult for the body to remove [4]. Mg has the highest corrosion rate, which could negatively affect tissues by releasing too much hydrogen and, because of this, the mechanical integrity of the stents can be compromised prior to the time needed for tissue repair. Pure Zn exhibits a high chemical activity, with an electrode potential of -0.762 V (SHE), which falls between that of magnesium at -2.372 V (SHE) and iron -0.44 V (SHE) [6; 7]. Because Zn has a less negative potential compared to Mg, this reduces the chances of forming Zn\({}^{2+}\) compared to the formation of Mg\({}^{2+}\). Iron has a lower negative potential compared to the other two metals, which implies that the ejection of Fe ions is more difficult. Thus, based on electrode potentials, Zn could have an optimal corrosion rate in vivo versus Fe or Mg. The biodegradable metals are highly reactive and prone to corrosion under physiological conditions. Several degradation models have been proposed in the literature [3; 8]. Generally, corrosion occurs via cathodic and anodic reactions in a near neutral (pH around 7.4) physiological environment. Metals like Mg produce oxides, hydroxides, and hydrogen gas as byproducts during their corrosion [4]. Zn also undergoes similar reaction processes, as stated below, but, unlike with Mg, this process does not produce hydrogen gas.