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The detrimental effects of blast loads can lead to severe damage in buildings, causing the collapse of structural components. This study focuses on a parametric analysis of blast loads on a Reinforced Concrete (RC) structure in SAP2000 for analysis. The research aims to assess how blast pressure, base reaction, and deformation vary with changes in explosive mass and standoff distances. To determine blast reactions, non-linear time history analysis is conducted through 16 different cases, involving varying distances and explosive masses. The findings reveal that an increase in explosive mass and a decrease in standoff distance result in elevated blast pressure, rendering the structure more susceptible to performance deterioration.

Autonomous manipulation at the microscale has applications in both the manufacturing and biomedical industries. However, independent actuation of multiple robots equipped with different manipulators is important for the speed and success of manipulation. In this paper, we have developed a specialized substrate with an array of microcoils that can generate local magnetic fields to control multiple microrobots independently. We have developed a physics based planning approach to compute the paths for the microrobots that can avoid obstacles and are well-suited for execution by the array of microcoils for autonomous navigation. We have demonstrated the capability of the planner with simulation experiments and the effectiveness of the microcoil array in independent actuation of the microrobots with physical experiments. The limitations of the current system are presented and a modified microcoil array is proposed and analyzed for increased performance.

Robots the size of several microns have numerous application in medicine, biology, and manufacturing. However, simultaneous control of multiple robots at this scale is difficult since the robot itself is too small to carry power, sensors, communication, and control on-board. In this paper, we have summarized different approaches, ranging from specialized robot design and fabrication to specialized ways of actuating robots, with the aim of independent control of a team/swarm of microrobots. We have also discussed the challenges for each approach. In the light of the challenges, we have proposed some directions where the future researchers can focus in order to solve the problem of independent control of a team of microrobots.

We describe an indirect optical gripper for noninvasive micromanipulation of sensitive objects, such as cells. Our optical gripper, driven by dynamic holographic optical tweezers, consists of an arrangement of six silica beads, each held in place by an optical trap. The beads are moved so as to grip an object, which itself is not significantly exposed to laser light. Six beads are sufficient to grip an object reliably, consistent with robotics design rules. We find that improved gripping is achieved when beads are arranged into groups of triplets, since each triplet of trapped beads forms a weakly attractive pocket into which other objects are drawn.

Collective cell migration often involves notable cell–cell and cell–substrate adhesions and highly coordinated motion of touching cells. We focus on the interplay between cell–substrate adhesion and cell–cell adhesion. We show that the loss of cell-surface contact does not significantly alter the dynamic pattern of protrusions and retractions of fast migrating amoeboid cells (Dictyostelium discoideum), but significantly changes their ability to adhere to other cells. Analysis of the dynamics of cell shapes reveals that cells that are adherent to a surface may coordinate their motion with neighbouring cells through protrusion waves that travel across cell–cell contacts. However, while shape waves exist if cells are detached from surfaces, they do not couple cell to cell. In addition, our investigation of actin polymerization indicates that loss of cell-surface adhesion changes actin polymerization at cell–cell contacts. To further investigate cell–cell/cell–substrate interactions, we used optical micromanipulation to form cell–substrate contact at controlled locations. We find that both cell-shape dynamics and cytoskeletal activity respond rapidly to the formation of cell–substrate contact.