it has the potential to create functional segments of a nanorobot. The 3D printer uses a liquid resin, which is hardened at precisely the correct spots by a focused laser beam. The focal point of the laser beam is guided through the resin by movable mirrors and leaves behind a hardened line of solid polymer, just a few hundred nanometers wide. This fine resolution enables the creation of intricately structured sculptures as tiny as a grain of sand. This process takes place by using photoactive resins, which are hardened by the laser at an extremely small scale to create the structure. This process is quick by nanoscale 3D printing standards. Ultra-small features can be made with the 3D micro-fabrication technique used in multiphoton photopolymerisation. This approach uses a focused laser to trace the desired 3D object into a block of gel. Due to the nonlinear nature of photo excitation, the gel is cured to a solid only in the places where the laser was focused while the remaining gel is then washed away. Feature sizes of under 100 nm are easily produced, as well as complex structures with moving and interlocked parts. Challenges in designing nanorobots There are number of challenges and problems that should be addressed when designing and building nanoscale machines with movable parts. The most obvious one is the need of developing very fine tools and manipulation techniques capable of assembling individual nanostructures with high precision into operational device. Less evident challenge is related to peculiarities of adhesion and friction on nanoscale. It is impossible to take existing design of macroscopic device with movable parts and just reduce it to the nanoscale. Such approach will not work due to high surface energy of nanostructures, which means that all contacting parts will stick together following the energy minimization principle. The adhesion and static friction between parts can easily exceed the strength of materials, so the parts will break before they start to move relative to each other. This leads to the need to design movable structures with minimal contact area []. In spite of the fast development of nanorobots, most of the nanorobots designed for drug delivery purposes, there is "still a long way to go before their commercialization and clinical applications can be achieved." Potential uses Nanomedicine Potential uses for nanorobotics in medicine include early diagnosis and targeted drug-delivery for cancer, biomedical instrumentation, surgery, pharmacokinetics, monitoring of